Eyewear with chroma enhancement

ABSTRACT

Some embodiments provide a lens including a lens body and an optical filter configured to attenuate visible light in certain spectral bands. At least some of the spectral bands can include spectral features that tend to substantially increase the colorfulness, clarity, and/or vividness of a scene. In certain embodiments, eyewear incorporates an optical filter that enhances chroma within one or more spectral hands. In some embodiments, a wearer of the eyewear can perceive the increase in chroma when viewing at least certain types of scenes.

INCORPORATION BY REFERENCE OF RELATED APPLICATIONS

The present application is a continuation of U.S. patent applicationSer. No. 15/436,137, filed Feb. 17, 2017, now U.S. Pat. No. 9,910,297,which claims priority as a continuation of U.S. patent application Ser.No. 14/593,844, filed Jan. 9, 2015, now U.S. Pat. No. 9,575,335, whichclaims the benefit of priority under 35 USC § 119 of U.S. ProvisionalPatent Application No. 61/926,228, filed Jan. 10, 2014, titled EYEWEARWITH CHROMA ENHANCEMENT FOR SPECIFIC ACTIVITIES. The entire contents ofthe above referenced applications are incorporated by reference hereinand made part of this specification.

BACKGROUND Field

This disclosure relates generally to eyewear and to lenses used ineyewear.

Description of Related Art

Eyewear can include optical elements that attenuate light in one or morewavelength bands. For example, sunglasses typically include a lens thatabsorbs a significant portion of light in the visible spectrum. Asunglass lens can have a dark film or coating that strongly absorbsvisible light, thereby significantly decreasing the luminoustransmittance of the lens. A lens can also be designed to have aspectral profile for another purpose, such as, for example, for indooruse, for use in sporting activities, for another particular use, or fora combination of uses.

SUMMARY

Example embodiments described herein have several features, no singleone of which is indispensable or solely responsible for their desirableattributes. Without limiting the scope of the claims, some of theadvantageous features will now be summarized.

Some embodiments provide a lens including a lens body and an opticalfilter within and/or outside of the lens body configured to attenuatevisible light in a plurality of spectral bands. In some embodiments inwhich the optical filter is within the lens body, the optical filter canconstitute the lens body, or the optical filter and additionalcomponents can constitute the lens body. The optical filter can beconfigured to substantially increase the colorfulness, clarity, and/orvividness of a scene. The optical filter can be particularly suited foruse with eyewear and can allow the wearer of the eyewear to view a scenein high definition color (HD color). Each of the plurality of spectralbands can include an absorbance peak with a spectral bandwidth, amaximum absorbance, and an integrated absorptance peak area within thespectral bandwidth. The spectral bandwidth can be defined as the fullwidth of the absorbance peak at 50% of the maximum absorbance of theabsorbance peak, the full width of the absorbance peak at 80% of themaximum absorbance of the absorbance peak, the full width of theabsorbance peak at 90% of the maximum absorbance of the absorbance peak,or the full width of the absorbance peak at 95% of the maximumabsorbance of the absorbance peak. Many other suitable definitions arepossible. In some embodiments, an attenuation factor obtained bydividing the integrated absorptance peak area within the spectralbandwidth by the spectral bandwidth of the absorbance peak can begreater than or equal to about 0.8 for the absorbance peak in at leastsome of the plurality of spectral bands. In some embodiments, thespectral bandwidth of the absorbance peak in each of the plurality ofspectral bands can be greater than or equal to about 5 nm and less thanor equal to about 50 nm.

In certain embodiments, the optical filter is at least partiallyincorporated into the lens body. The lens body can be impregnated with,loaded with, or otherwise comprise one or more organic dyes. Each of theone or more organic dyes can be configured to produce the absorbancepeak in one of the plurality of spectral bands. In some embodiments, theoptical filter is at least partially incorporated into a lens coatingdisposed over the lens body. For example, one or more of the organicdyes can include an absorbance profile having a blue light absorbancepeak with a center wavelength and/or peak location between about 470 nmand about 490 nm. In some embodiments, the spectral bandwidth of theblue light absorbance peak can be greater than or equal to about 20 nm,and the attenuation factor of the blue light absorbance peak can begreater than or equal to about 0.8.

One or more of the plurality of organic dyes can include an absorbanceprofile having a yellow light or yellow-green light absorbance peak witha center wavelength and/or peak location between about 560 nm and about580 nm. In some embodiments, the spectral bandwidth of the yellow lightor yellow-green light absorbance peak can be greater than or equal toabout 20 nm, and the attenuation factor of the yellow light oryellow-green light absorbance peak can be greater than or equal to about0.8.

One or more of the plurality of organic dyes can include an absorbanceprofile having a red light or orange-red light absorbance peak with acenter wavelength and/or peak location between about 600 nm and about680 nm. In some embodiments, the spectral bandwidth of the red light ororange-red light absorbance peak can be greater than or equal to about20 nm, and the attenuation factor of the red light absorbance peak isgreater than or equal to about 0.8.

Some embodiments provide a method of manufacturing a lens. The methodcan include forming a lens having an optical filter configured toattenuate visible light in a plurality of spectral bands. Each of theplurality of spectral bands can include an absorbance peak with aspectral bandwidth, a maximum absorbance, and an integrated absorptancepeak area within the spectral bandwidth. An attenuation factor of theabsorbance peak in each of the plurality of spectral bands can begreater than or equal to about 0.8 and less than 1.

In certain embodiments, a lens can be formed by forming a lens body andforming a lens coating over the lens body. At least a portion of theoptical filter can be incorporated into the lens body or the lenscoating. In various embodiments, the lens coating can include aninterference coating.

In some embodiments, a lens body can be formed by a method includingforming a plurality of lens body elements and coupling the lens bodyelements to one another using one or more adhering layers. A polarizingfilm can be disposed between two or more of the plurality of lens bodyelements. In some embodiments, the polarizing film can be insert moldedwithin the lens body. In various embodiments, the lens can include oneor more components that substantially absorb ultraviolet radiation,including near ultraviolet radiation.

Some embodiments provide a lens that includes a lens body with anoptical filter configured to increase the average chroma value of lighttransmitted through the lens within one or more portions of the visiblespectrum. The chroma value is the C* attribute of the CIE L*C*h* colorspace. At least one portion of the visible spectrum can include aspectral range between about 440 nm and about 490 nm, between about 540nm and about 580 nm, or between about 630 nm and about 660 nm. Theincrease in average chroma value can include an increase that isperceivable by a human with substantially normal vision.

In certain embodiments, the optical filter is configured to increase theaverage chroma value of light transmitted through the lens within one ormore portions of the visible spectrum by a relative magnitude of greaterthan or equal to about 3% compared to the average chroma value of lighttransmitted through a neutral filter within the same spectral range.

The optical filter can be configured to increase the average chromavalue of light transmitted through the lens within one or more portionsof the visible spectrum by a relative magnitude of greater than or equalto about 15% compared to the average chroma value of light transmittedthrough a neutral filter within the same spectral range.

In some embodiments, the optical filter does not substantially decreasethe average chroma value of light transmitted through the lens withinthe one or more portions of the visible spectrum when compared to theaverage chroma value of light transmitted through a neutral filter.

Certain embodiments provide a lens including a lens body and an opticalfilter configured to attenuate visible light in a plurality of spectralbands. Each of the plurality of spectral bands includes an absorbancepeak with a spectral bandwidth, a maximum absorbance, lower and upperedge portions that are substantially below the maximum absorbance, and amiddle portion positioned between the lower and upper edge portions andincluding the maximum absorbance and a region substantially near themaximum absorbance. In some embodiments, one of the lower or upper edgeportions of at least one absorbance peak lies within an object spectralwindow including a spectral region in which the object emits or reflectsa substantial visible stimulus.

The optical filter can be configured such that one of the lower or upperedge portions of at least one absorbance peak lies within a backgroundspectral window. The background spectral window includes a spectralregion in which the background emits or reflects a substantial visiblestimulus.

One aspect of the embodiments disclosed herein is implemented in aneyewear comprising a lens comprising an optical filter. The opticalfilter is configured to attenuate visible light in at least a firstspectral band and a second spectral band. Each of the first and secondspectral bands comprise an absorbance peak with a spectral bandwidth; amaximum absorbance; a center wavelength located at a midpoint of thespectral bandwidth; and an integrated absorptance peak area within thespectral bandwidth. The spectral bandwidth is equal to the full width ofthe absorbance peak at 80% of the maximum absorbance of the absorbancepeak. The first spectral band comprises a first absorbance peak having afirst center wavelength in the wavelength range between about 450 nm andabout 490 nm and the second spectral band comprises a second absorbancepeak having a second center wavelength in the wavelength range betweenabout 550 nm and about 590 nm. An attenuation factor of the first andsecond absorbance peaks is greater than or equal to about 0.8 and lessthan 1, wherein the attenuation factor of an absorbance peak is obtainedby dividing an integrated absorptance peak area within the spectralbandwidth by the spectral bandwidth of the absorbance peak. The lens hasa CIE chromaticity x value between about 0.35 and 0.5. The opticalfilter can be configured to increase the average chroma value of uniformintensity light stimuli having a bandwidth of 30 nm transmitted throughthe lens at least partially within the first spectral band by an amountbetween about 10% and about 25%. The eyewear can be adapted to viewobjects on a surface of water or underwater.

Another aspect of the embodiments disclosed herein is implemented in aneyewear comprising a lens comprising an optical filter. The opticalfilter is configured to attenuate visible light in at least a firstspectral band, a second spectral band and a third spectral band. Each ofthe first, second and third spectral bands comprises an absorbance peakwith a spectral bandwidth; a maximum absorbance; a center wavelengthlocated at a midpoint of the spectral bandwidth, and an integratedabsorptance peak area within the spectral bandwidth. The spectralbandwidth is equal to the full width of the absorbance peak at 80% ofthe maximum absorbance of the absorbance peak. The first spectral bandcomprises a first absorbance peak having a first center wavelength inthe wavelength range between about 450 nm and about 490 nm. The secondspectral band comprises a second absorbance peak having a second centerwavelength in the wavelength range between about 550 nm and about 590nm. The third spectral band comprises a second absorbance peak having athird center wavelength in the wavelength range between about 630 nm andabout 670 nm. An attenuation factor of the first and second absorbancepeaks is greater than or equal to about 0.8 and less than 1 and anattenuation factor of the third absorbance peak is greater than or equalto about 0.3 and less than or equal to 0.8, wherein the attenuationfactor of an absorbance peak is obtained by dividing an integratedabsorptance peak area within the spectral bandwidth by the spectralbandwidth of the absorbance peak. The lens can have a CIE chromaticity xvalue between about 0.35 and 0.5. The optical filter can be configuredto increase the average chroma value of uniform intensity light stimulihaving a bandwidth of 30 nm transmitted through the lens at leastpartially within the first spectral band by an amount between about 20%and about 40%. The eyewear can be adapted to view objects on grass.

Yet another aspect of the embodiments disclosed herein is implemented inan eyewear comprising a lens comprising an optical filter. The opticalfilter is configured to attenuate visible light in at least a firstspectral band and a second spectral band. Each of the first and secondspectral bands comprises an absorbance peak with a spectral bandwidth; amaximum absorbance; a center wavelength located at a midpoint of thespectral bandwidth; and an integrated absorptance peak area within thespectral bandwidth. The spectral bandwidth is equal to the full width ofthe absorbance peak at 80% of the maximum absorbance of the absorbancepeak. The first spectral band comprises a first absorbance peak having afirst center wavelength in the wavelength range between about 450 nm andabout 490 nm and the second spectral band comprises a second absorbancepeak having a second center wavelength in the wavelength range betweenabout 630 nm and about 670 nm. An attenuation factor of the firstabsorbance peak is greater than or equal to about 0.8 and less than 1and an attenuation factor of the third absorbance peak is greater thanor equal to about 0.4 and less than or equal to 0.9, wherein theattenuation factor of an absorbance peak is obtained by dividing anintegrated absorptance peak area within the spectral bandwidth by thespectral bandwidth of the absorbance peak. The lens can have a CIEchromaticity x value between about 0.35 and 0.5. The optical filter canbe configured to increase the average chroma value of uniform intensitylight stimuli having a bandwidth of 30 nm transmitted through the lensat least partially within the first spectral band by an amount betweenabout 20% and about 40%. The eyewear can be adapted to view objects onsnow.

BRIEF DESCRIPTION OF THE DRAWINGS

Various embodiments are depicted in the accompanying drawings forillustrative purposes, and should in no way be interpreted as limitingthe scope of the inventions. In addition, various features of differentdisclosed embodiments can be combined to form additional embodiments,which are part of this disclosure. Any feature or structure can beremoved or omitted. Throughout the drawings, reference numbers can bereused to indicate correspondence between reference elements.

FIG. 1A is a perspective view of a pair of spectacles incorporatinglenses with a chroma-enhancing optical filter.

FIG. 1B is a cross-sectional view of one of the lenses shown in FIG. 1A.

FIG. 2A is a graph showing sensitivity curves for cone photoreceptorcells in the human eye.

FIG. 2B is a graph showing the 1931 CIE XYZ tristimulus functions.

FIG. 3 is a graph showing the luminous efficiency profile of the humaneye.

FIGS. 4A, 4B and 4C illustrate spectral characteristics of animplementation of optical filter that can be included in differentembodiments of activity specific lenses.

FIGS. 5A, 5B and 5C illustrate spectral characteristics of animplementation of optical filter that can be included in differentembodiments of activity specific lenses.

FIGS. 6A, 6B and 6C illustrate spectral characteristics of animplementation of optical filter that can be included in differentembodiments of activity specific lenses.

FIGS. 7A, 7B and 7C illustrate spectral characteristics of animplementation of optical filter that can be included in differentembodiments of activity specific lenses.

FIGS. 8A, 8B and 8C illustrate spectral characteristics of animplementation of optical filter that can be included in differentembodiments of activity specific lenses.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

Although certain preferred embodiments and examples are disclosed below,inventive subject matter extends beyond the specifically disclosedembodiments to other alternative embodiments and/or uses, and tomodifications and equivalents thereof. Thus, the scope of the claimsappended hereto is not limited by any of the particular embodimentsdescribed below. For example, in any method or process disclosed herein,the acts or operations of the method or process can be performed in anysuitable sequence and are not necessarily limited to any particulardisclosed sequence. Various operations can be described as multiplediscrete operations in turn, in a manner that can be helpful inunderstanding certain embodiments; however, the order of descriptionshould not be construed to imply that these operations are orderdependent. Additionally, the structures described herein can be embodiedas integrated components or as separate components. For purposes ofcomparing various embodiments, certain aspects and advantages of theseembodiments are described. Not necessarily all such aspects oradvantages are achieved by any particular embodiment. Thus, for example,various embodiments can be carried out in a manner that achieves oroptimizes one advantage or group of advantages as taught herein withoutnecessarily achieving other aspects or advantages as can also be taughtor suggested herein.

Objects that humans can visually observe in the environment typicallyemit, reflect, or transmit visible light from one or more surfaces. Thesurfaces can be considered an array of points that the human eye isunable to resolve any more finely. Each point on the surfaces does notemit, reflect, or transmit a single wavelength of light; rather, itemits, reflects, or transmits a broad spectrum of wavelengths that areinterpreted as a single color in human vision. Generally speaking, ifone were to observe the corresponding “single wavelength” of light forthat interpreted color (for example, a visual stimulus having a verynarrow spectral bandwidth, such as 1 nm), it would appear extremelyvivid when compared to a color interpreted from a broad spectrum ofobserved wavelengths.

An optical filter can be configured to remove the outer portions of abroad visual stimulus to make colors appear more vivid as perceived inhuman vision. The outer portions of a broad visual stimulus refer towavelengths that, when substantially, nearly completely, or completelyattenuated, decrease the bandwidth of the stimulus such that thevividness of the perceived color is increased. An optical filter foreyewear can be configured to substantially increase the colorfulness,clarity, and/or vividness of a scene. Such an optical filter for eyewearcan allow the wearer to view the scene in high definition color (HDcolor). In some embodiments, portions of a visual stimulus that are notsubstantially attenuated include at least the wavelengths for which conephotoreceptor cells in the human eye have the greatest sensitivity. Incertain embodiments, the bandwidth of the color stimulus when theoptical filter is applied includes at least the wavelengths for whichthe cone photoreceptor cells have the greatest sensitivity. In someembodiments, a person wearing a lens incorporating an optical filterdisclosed herein can perceive a substantial increase in the clarity of ascene. The increase in perceived clarity can result, for example, fromincreased contrast, increased chroma, or a combination of factors.

The vividness of interpreted colors is correlated with an attributeknown as the chroma value of a color. The chroma value is one of theattributes or coordinates of the CIE L*C*h* color space. Together withattributes known as hue and lightness, the chroma can be used to definecolors that are perceivable in human vision. It has been determined thatvisual acuity is positively correlated with the chroma values of colorsin an image. In other words, the visual acuity of an observer is greaterwhen viewing a scene with high chroma value colors than when viewing thesame scene with lower chroma value colors.

An optical filter can be configured to enhance the chroma profile of ascene when the scene is viewed through a lens that incorporates theoptical filter. The optical filter can be configured to increase ordecrease chroma in a plurality of spectral ranges (e.g., two spectralranges, three spectral ranges, four spectral ranges or five spectralranges) in order to achieve any desired effect. The spectral ranges overwhich an optical filter increases or decreases chroma can be calledchroma enhancement windows (CEWs). The chroma-enhancing optical filtercan be configured to preferentially transmit or attenuate light in anydesired chroma enhancement windows. Any suitable process can be used todetermine the desired chroma enhancement windows. For example, thecolors predominantly reflected or emitted in a selected environment canbe measured, and a filter can be adapted to provide chroma enhancementin one or more spectral regions corresponding to the colors that arepredominantly reflected or emitted.

In some embodiments, CEWs include portions of the visible spectrum inwhich an optical filter provides a substantial change in chroma comparedto a neutral filter having the same average attenuation within each 30nm stimulus band, as perceived by a person with normal vision. Incertain cases, a substantial enhancement of chroma can be seen when afilter provides a chroma increase greater than or equal to about 2%compared to the neutral filter. In other cases, a chroma increasegreater than or equal to about 3% or greater than or equal to about 5%compared to the neutral filter is considered a substantial increase.Whether a chroma change represents a substantial increase can depend onthe spectral region in which the increase is provided. For example, asubstantial chroma enhancement can include an increase in chroma greaterthan or equal to about 6% over a neutral filter when the visual stimulusis centered at about 560 nm. A substantial chroma enhancement caninclude an increase in chroma greater than or equal to about 3% over aneutral filter when the visual stimulus is centered at about 660 nm. Asubstantial chroma enhancement can include an increase in chroma greaterthan or equal to about 15% over a neutral filter when the visualstimulus is centered at about 570 nm. Accordingly, the amount of changein chroma relative to the neutral filter that is considered substantialcan differ depending on the spectral range of the CEW.

In certain embodiments, a substantial chroma enhancement is provided byan optical filter configured to increase chroma in one or more CEWs overa neutral filter without any significant decrease in chroma compared toa neutral filter within the one or more CEWs. A substantial chromaenhancement can also be provided by an embodiment of an optical filterconfigured to increase chroma in one or more CEWs over a neutral filterwithout any significant decrease in chroma compared to a neutral filterwithin a particular spectral range, such as, for example, between about420 nm and about 650 nm.

In the embodiment illustrated in FIG. 1A, eyewear 100 includes lenses102 a, 102 b having a chroma-enhancing optical filter. Thechroma-enhancing filter generally changes the colorfulness of a sceneviewed through one or more lenses 102 a, 102 b, compared to a sceneviewed through a lens with a neutral density optical filter having thesame luminous transmittance as the chroma-enhancing filter. The eyewearcan be of any type, including general-purpose eyewear, special-purposeeyewear, sunglasses, driving glasses, sporting glasses, indoor eyewear,outdoor eyewear, vision-correcting eyewear, contrast-enhancing eyewear,eyewear designed for another purpose, or eyewear designed for acombination of purposes.

In the embodiment illustrated in FIG. 1B, a lens 102 incorporatesseveral lens elements. The lens elements include a lens coating 202, afirst lens body element 204, a film layer 206, and a second lens bodyelement 208. Many variations in the configuration of the lens 102 arepossible. For example, the lens 102 can include a polarizing layer, oneor more adhesive layers, a photochromic layer, an antireflectioncoating, a mirror coating, an interference coating, a scratch resistantcoating, a hydrophobic coating, an anti-static coating, other lenselements, or a combination of lens components. If the lens 102 includesa photochromic layer, the photochromic material can include a neutraldensity photochromic or any other suitable photochromic. At least someof the lens components and/or materials can be selected such that theyhave a substantially neutral visible light spectral profile.Alternatively, the visible light spectral profiles can cooperate toachieve any desired lens chromaticity, a chroma-enhancing effect,another goal, or any combination of goals. The polarizing layer, thephotochromic layer, and/or other functional layers can be incorporatedinto the film layer 206, the lens coating 202, one or more of the lensbody elements 204, 208, or can be incorporated into additional lenselements. In some embodiments, a lens 102 incorporates fewer than allthe lens elements shown in FIG. 1B.

The lens can include a UV absorption layer or a layer that includes UVabsorption outside of the optical filter layer. Such a layer candecrease bleaching of the optical filter. In addition, UV absorbingagents can be disposed in any lens component or combination of lenscomponents.

The lens body elements 204, 208 can be made from glass, a polymericmaterial, a co-polymer, a doped material, another material, or acombination of materials. In some embodiments, one or more portions ofthe optical filter can be incorporated into the lens coating 202, intoone or more lens body elements 204, 208, into a film layer 206, into anadhesive layer, into a polarizing layer, into another lens element, orinto a combination of elements.

The lens body elements 204, 208 can be manufactured by any suitabletechnique, such as, for example, casting or injection molding. Injectionmolding can expose a lens to temperatures that degrade or decomposecertain dyes. Thus, when the optical filter is included in one or morelens body elements, a wider range of dyes can be selected for inclusionin the optical filter when the lens body elements are made by castingthan when the lens body is made by injection molding. Further, a widerrange of dyes or other optical filter structures can be available whenthe optical filter is implemented at least partially in a lens coating.

With reference to FIGS. 1A and 1B, eyewear can include a frame andlenses 102 a and 102 b The lenses 102 a and 102 b have a filter thatenhances chroma in a wavelength-conversion window, a background-window,a spectral-width window, another CEW, or any combination of CEWs. Forsome applications, the spectral-width window can be omitted. For otherapplications, an object-specific spectral window is provided that caninclude the wavelength-conversion window. The lenses 102 a and 102 b canbe corrective lenses or non-corrective lenses and can be made of any ofa variety of optical materials including glasses or plastics such asacrylics or polycarbonates. The lenses can have various shapes,including piano-plano and meniscus shapes. In alternative eyewear, aframe is configured to retain a unitary lens that is placed in front ofboth eyes when the eyewear is worn. Goggles can also be provided thatinclude a unitary lens that is placed in front of both eyes when thegoggles are worn.

A sunglass lens substantially attenuates light in the visible spectralregion. However, the light need not be attenuated uniformly or evengenerally evenly across the visible spectrum. Instead, the light that isattenuated can be tailored to achieve a specific chroma-enhancingprofile or another goal. A sunglass lens can be configured to attenuatelight in spectral bands that are selected such that the scene receivesone or more of the improvements or characteristics disclosed herein.Such improvements or characteristics can be selected to benefit thewearer during one or more particular activities or in one or morespecific environments.

To design a filter that increases chroma for an array of colors, one canaccount for the mechanisms involved in the eye's perception of color.The photopically adapted eye (e.g., the human eye) shows peaksensitivities at 440, 545, and 565 nm. These peak sensitivitiescorrespond to each of three optical sensors found in the eye's retinaknown as cones. The location and shape of the cone sensitivity profileshave recently been measured with substantial accuracy in Stockman andSharpe, “The spectral sensitivities of the middle- andlong-wavelength-sensitive cones derived from measurements in observersof known genotype,” Vision Research 40 (2000), pp. 1711-1737, which isincorporated by reference herein and made a part of this specification.The sensitivity profiles S, M, L for cone photoreceptor cells in thehuman eye as measured by Stockman and Sharpe are shown in FIG. 2A.

The cone sensitivity profiles can be converted from sensitivity data toquantities describing color such as, for example, the CIE tristimuluscolor values. The 1931 CIE XYZ tristimulus functions are shown in FIG.2B. In some embodiments, the CIE tristimulus color values are used todesign an optical filter. For example, the CIE color values can be usedto calculate the effect of an optical filter on perceived color usingvalues of chroma, C*, in the CIE L*C*h* color space.

The human cone sensitivities can be converted to the 1931 CIE XYZ colorspace using the linear transformation matrix M described in Golz andMacleod, “Colorimetry for CRT displays.” J. Opt. Soc. Am. A vol. 20, no.5 (May 2003), pp. 769-781, which is incorporated by reference herein andmade a part of this specification. The linear transformation is shown inEq. 1:

$\begin{matrix}{M = {{\begin{bmatrix}0.17156 & 0.52901 & 0.02199 \\0.15955 & 0.48553 & 0.04298 \\0.01916 & 0.03989 & 1.03993\end{bmatrix}\begin{bmatrix}L \\M \\S\end{bmatrix}} = {M\begin{bmatrix}X \\Y \\Z\end{bmatrix}}}} & ( {{Eq}.\mspace{14mu} 1} )\end{matrix}$To solve for the 1931 CIE XYZ color space values (X Y Z), the Stockmanand Sharpe 2000 data can be scaled by factors of 0.628, 0.42, and 1.868for L. M, and S cone sensitivities, respectively, and multiplied by theinverse of the linear transformation matrix M in the manner shown inEqs. 2-1 and 2-2:

$\begin{matrix}{\begin{bmatrix}X \\Y \\Z\end{bmatrix} = {M^{- 1}\begin{bmatrix}L \\M \\S\end{bmatrix}}} & ( {{{Eq}.\mspace{14mu} 2}\text{-}1} )\end{matrix}$where:

$\begin{matrix}{M^{- 1} = \begin{bmatrix}2.89186 & {- 3.13517} & 0.19072 \\0.95178 & 1.02077 & {- 0.02206} \\{- 0.01677} & 0.09691 & 0.95724\end{bmatrix}} & ( {{{Eq}.\mspace{14mu} 2}\text{-}2} )\end{matrix}$

The CIE tristimulus values, X Y Z, can be converted to the 1976 CIEL*a*b* color space coordinates using the nonlinear equations shown inEqs. 3-1 through 3-7. Where X_(n)=95.02, Y_(n)=100.00, and Z_(n)=108.82,L*=116³√{square root over (Y/Y _(n))}−16  (Eq. 3-1)a*=500(²√{square root over (X/X _(n))}−³√{square root over (Y/Y_(n))})  (Eq 3-2)b*=200(³√{square root over (Y/Y _(n))}−³√{square root over (Z/Z_(n))})  (Eq 3-3)If X/X_(n), Y/Y_(n), or Z/Z_(n)<0.008856, then:L*=903.3(Y/Y _(n))  (Eq. 3-4)a*=500[f(X/X _(n))−f(Y/Y _(n))]  (Eq 3-5)b*=200[f(Y/Y _(n))−f(Z/Z _(n))]  (Eq. 3-6)For α>0.008856, α=X/X_(n), Y/Y_(n), or Z/Z_(n)f(α)=³√{square root over (α)}Otherwise:f(a)=7.87a+16/116  (Eq. 3-7)Chroma or C* can be then be calculated by further conversion from CIEL*a*b* to CIE L*C*h* using Eq. 4:C*=√{square root over (a* ² +b* ²)}  (Eq. 4)

As mentioned above, the colors observed in the physical world arestimulated by wide bands of wavelengths. To simulate this and thencalculate the effects of an optical filter, filtered and non-filteredbands of light are used as input to the cone sensitivity space. Theeffect on chroma can then be predicted via the transformations listedabove.

When inputting a spectrum of light to the cone sensitivity space, themechanism of color recognition in the human eye can be accounted for.Color response by the eye is accomplished by comparing the relativesignals of each of the three cones types: S, M, and L. To model thiswith broad band light, a sum of the intensities at each wavelength inthe input spectrum is weighted according to the cone sensitivity at thatwavelength. This is repeated for all three cone sensitivity profiles. Anexample of this calculation is shown in Table A:

TABLE A Input light L intensity, Weighted Wavelength arbitrary L Conelight λ (nm) units Sensitivity intensity 500 0.12 × 0.27 = 0.032 5010.14 × 0.28 = 0.039 502 0.16 × 0.31 = 0.05 503 0.17 × 0.33 = 0.056 5040.25 × 0.36 = 0.09 505 0.41 × 0.37 = 0.152 506 0.55 × 0.39 = 0.215 5070.64 × 0.41 = 0.262 508 0.75 × 0.42 = 0.315 509 0.63 × 0.44 = 0.277 5100.54 × 0.46 = 0.248 511 0.43 × 0.48 = 0.206 512 0.25 × 0.49 = 0.123 5130.21 × 0.50 = 0.105 514 0.18 × 0.51 = 0.092 515 0.16 × 0.52 = 0.083 5160.15 × 0.54 = 0.081 517 0.13 × 0.56 = 0.073 518 0.11 × 0.57 = 0.063 5190.09 × 0.59 = 0.053 Total weighted 520 0.08 × 0.61 = 0.049 lightintensity, normalized Sum 6.15 2.664 0.433

Normalized weighted light intensities for all three cone types can thenbe converted to the 1931 CIE XYZ color space via a linear transformationmatrix, M. This conversion facilitates further conversion to the 1976CIE L*a*b* color space and the subsequent conversion to the CIE L*C*hcolor space to yield chroma values.

To simulate the effect of a filter placed between the eye and thephysical world, an input band of light can be modified according to aprospective filter's absorption characteristics. The weighted lightintensity is then normalized according to the total sum of light that istransmitted through the filter.

In certain embodiments, to test the effect of a filter on various colorsof light, the spectral profile, or at least the bandwidth, of an inputis determined first. The appropriate bandwidth for the model's input istypically affected by the environment of use for the optical filter. Areasonable bandwidth for a sunglass lens can be about 30 nm, since thisbandwidth represents the approximate bandwidth of many colors perceivedin the natural environment. Additionally, 30 nm is a narrow enoughbandwidth to permit transmitted light to fall within responsive portionsof the cone sensitivity functions, which are approximately twice thisbandwidth. A filter designed using a 30 nm input bandwidth will alsoimprove the chroma of colors having other bandwidths, such as 20 nm or80 nm. Thus, the effect of a filter on chroma can be determined usingcolor inputs having a 30 nm bandwidth or another suitable bandwidth thatis sensitive to a wide range of natural color bandwidths.

Other bandwidths are possible. The bandwidth can be significantlywidened or narrowed from 30 nm while preserving the chroma-enhancingproperties of many filter designs. The 30 nm bandwidth described aboveis representative of wider or narrower input bandwidths that can be usedto produce desired features of an optical filter. The term “bandwidth”is used herein in its broad and ordinary sense. This disclosure setsforth several techniques for characterizing the bandwidth of a spectralfeature. Unless otherwise specified, any suitable bandwidthcharacterization disclosed herein can be applied to define the spectralfeatures identified in this specification. For example, in someembodiments, the bandwidth of a peak encompasses the full width of apeak at half of the peak's maximum value (FWHM value) and any othercommonly used measurements of bandwidth.

A sample calculation of the normalized L weighted light intensity usingthe 30 nm bandwidth and an example filter is shown in Table B:

TABLE B Incoming Filtered light L intensity weighted Wavelengtharbitrary Filter L Cone light λ (nm) units T % Sensitivity intensity 4990 × 0.12 × 0.25 = 0.00 500 1 × 0.34 × 0.27 = 0.09 501 1 × 0.41 × 0.28 =0.11 502 1 × 0.42 × 0.31 = 0.13 503 1 × 0.44 × 0.33 = 0.15 504 1 × 0.51× 0.36 = 0.18 505 1 × 0.55 × 0.37 = 0.20 506 1 × 0.61 × 0.39 = 0.24 5071 × 0.78 × 0.41 = 0.32 508 1 × 0.75 × 0.42 = 0.32 509 1 × 0.85 × 0.44 =0.37 510 1 × 0.87 × 0.46 = 0.40 511 1 × 0.91 × 0.48 = 0.44 512 1 × 0.95× 0.49 = 0.47 513 1 × 0.96 × 0.50 = 0.48 514 1 × 0.97 × 0.51 = 0.49 5151 × 0.96 × 0.52 = 0.50 516 1 × 0.98 × 0.54 = 0.53 517 1 × 0.76 × 0.56 =0.43 518 1 × 0.75 × 0.57 = 0.43 519 1 × 0.61 × 0.59 = 0.36 520 1 × 0.55× 0.61 = 0.34 521 1 × 0.48 × 0.72 = 0.35 522 1 × 0.42 × 0.78 = 0.33 5231 × 0.41 × 0.81 = 0.33 524 1 × 0.35 × 0.84 = 0.29 525 1 × 0.33 × 0.85 =0.28 526 1 × 0.31 × 0.88 = 0.27 527 1 × 0.28 × 0.87 = 0.24 528 1 × 0.27× 0.89 = 0.24 529 1 × 0.72 × 0.91 = 0.20 Total Filtered 530 0 × 0.18 ×0.92 = 0.00 L Weighted 531 0 × 0.15 × 0.93 = 0.00 Light Intensity,Normalized Sum 30 18.4 9.51 0.52

In some embodiments, an optical filter is designed by using spectralprofiles of candidate filters to calculate the effect of the candidatefilters on chroma. In this way, changes in the filter can be iterativelychecked for their effectiveness in achieving a desired result.Alternatively, filters can be designed directly via numericalsimulation. Examples and comparative examples of optical filters and theeffects of those optical filters on chroma are described herein. In eachcase, the chroma of input light passing through each filter is comparedto the chroma of the same input without filtering. Plots of “absorptance%” against visible spectrum wavelengths show the spectral absorptanceprofile of the example or comparative example optical filter. Each plotof “chroma, C*, relative” against visible spectrum wavelengths shows therelative chroma of a 30 nm wide light stimulus of uniform intensityafter the stimulus passes through a wavelength-dependent optical filteras a thinner curve on the plot, with the center wavelength of eachstimulus being represented by the values on the horizontal axis. Eachplot of “chroma, C*, relative” also shows the relative chroma of thesame 30 nm wide light stimulus passing through a neutral filter thatattenuates the same average percentage of light within the bandwidth ofthe stimulus as the wavelength-dependent optical filter.

A CIE xy chromaticity diagram for various implementations of an opticalfilter is also disclosed herein. The chromaticity diagram shows thechromaticity of the filter as well as the gamut of an RGB color space.Each of the chromaticity diagrams provided in this disclosure shows thechromaticity of the associated filter or lens, where the chromaticity iscalculated using CIE illuminant D65.

One goal of filter design can be to determine the overall colorappearance of a lens. In some embodiments, the perceived color ofoverall light transmitted from the lens is bronze, amber, violet, gray,or another color. In some cases, the consumer has preferences that aredifficult to account for quantitatively. In certain cases, lens coloradjustments can be accomplished within the model described in thisdisclosure. The impact of overall color adjustments to the filter designcan be calculated using a suitable model. In some cases, coloradjustments can be made with some, little, or no sacrifice to the chromacharacteristics being sought. In some embodiments, a lens has an overallcolor with a relatively low chroma value. For example, the lens can havea chroma value of less than 60. A chroma-increasing optical filter usedin such a lens can provide increased colorfulness for at least somecolors as compared to when the same optical filter is used in a lenswith an overall color having a higher chroma value.

The spectral features of an optical filter can be evaluated byconsidering the transmittance profile of the filter and/or a lensincorporating the filter. In some embodiments, the bandwidth and/orattenuation factors of transmittance valleys can be measured. Thebandwidth of a transmittance valley can be defined, for example, as thefull width of the valley at a certain transmittance, such as 2%, 5%,10%, or 20% In certain embodiments, the bandwidth of a transmittancevalley is defined as the full width of the valley at 1.5 times, twotimes, four times, ten times, or one hundred times the minimumtransmittance. In some embodiments, the bandwidth of a transmittancevalley is defined as the full width of the valley at a certain offsetfrom the minimum transmittance, such as, for example, the minimumtransmittance plus 1% transmittance, plus 2% transmittance, plus 5%transmittance, plus 10% transmittance, or plus 20% transmittance. Theattenuation factor of a transmittance valley can be calculated bydividing the area between 100% and the transmittance profile curve bythe bandwidth, within the spectral bandwidth of the transmittancevalley. Alternatively, the attenuation factor of a transmittance valleycan be calculating by finding the absorptance within the bandwidth bysubtracting the area under the transmittance curve from 1 and dividingthe result by the bandwidth.

The spectral features of an optical filter can also be evaluated byconsidering the absorbance profile of the filter and/or a lensincorporating the filter. In some embodiments, an optical filter isconfigured to increase or maximize chroma in the blue to blue-greenregion of the visible spectrum. A filter with such a configuration canhave an absorbance peak centered in a wavelength range between about 445nm and about 490 nm. In some implementations, the full width at halfmaximum (FWHM) of the absorbance peak can be about 20 nm. However, inother implementations, the FWHM of the absorbance peak can be greaterthan or equal to about 10 nm, greater than or equal to about 15 nm,greater than or equal to about 20 nm, less than or equal to about 60 nm,less than or equal to about 50 nm, less than or equal to about 40 nm,between about 10 nm and about 60 nm, or between any of the otherforegoing values. The bandwidth of an absorbance peak can be measured inany suitable fashion in addition to or in place of FWHM. For example,the bandwidth of an absorbance peak can include the full width of a peakat 80%% of the maximum, the full width of a peak at 90% of the maximum,the full width of a peak at 95% of the maximum, or the full width of apeak at 98% of the maximum.

In some embodiments, an optical filter is configured to increase ormaximize chroma across several, many, or most colors, or at least manycolors that are commonly encountered in the environment of the wearer.Such an optical filter can include a plurality of absorbance peaks. Forexample, an embodiment of an optical filter configured to provide chromaenhancement at different colors can include three or more absorbancepeaks. For example, an implementation of a multicolor chroma enhancementoptical filter can have four absorbance peaks with center wavelengths atabout 415 nm, about 478 nm, about 574 nm, and about 715 nm. A relativechroma plot of such an optical filter will show that the implementationof the optical filter can provide a substantial increase in chroma in atleast four spectral windows compared to a neutral filter having the sameintegrated light transmittance within each 30 nm stimulus band as withineach corresponding band of the optical filter.

Many other variations in the location and number of absorbance peaks arepossible. For example, some embodiments significantly attenuate lightbetween about 558 nm and about 580 nm by providing a peak at about 574nm and adding an additional peak at about 561 nm. Such embodiments canprovide substantially greater chroma in the green region, including atwavelengths near about 555 nm.

In certain embodiments, an optical filter increases chroma in thevisible spectrum by increasing the degree to which light within thebandwidth of each absorbance peak is attenuated. The degree of lightattenuation within the spectral bandwidth of an absorbance peak can becharacterized by an “attenuation factor” defined as the integratedabsorptance peak area within the spectral bandwidth of the absorbancepeak divided by the spectral bandwidth of the absorbance peak. Anexample of an absorbance peak with an attenuation factor of 1 is asquare wave. Such an absorbance peak attenuates substantially all lightwithin its spectral bandwidth and substantially no light outside itsspectral bandwidth. In contrast, an absorbance peak with an attenuationfactor of less than 0.5 attenuates less than half of the light withinits spectral bandwidth and can attenuate a significant amount of lightoutside its spectral bandwidth.

In certain embodiments, an optical filter is configured to have one ormore absorbance peaks with an attenuation factor close to 1. Many otherconfigurations are possible. In some embodiments, an optical filter hasone or more absorbance peaks (or transmittance valleys) with anattenuation factor greater than or equal to about 0.8, greater than orequal to about 0.9, greater than or equal to about 0.95, greater than orequal to about 0.98, between about 0.8 and about 0.99, greater than orequal to about 0.8 and less than 1, or between any of the otherforegoing values. Any combination of one or more of the foregoinglimitations on attenuation factor can be called “attenuation factorcriteria.” In certain embodiments, the attenuation factor of eachabsorbance peak in an optical filter meets one or more of theattenuation factor criteria. In some embodiments, the attenuation factorof each absorbance peak having a maximum absorbance over a certainabsorbance threshold in an optical filter meets one or more of theattenuation factor criteria. The absorbance threshold can be about 0.5,about 0.7, about 0.9, about 1, between 0.5 and 1, or another value. Itis understood that while certain spectral features are described hereinwith reference to an optical filter, each of the spectral features canequally apply to the spectral profile of a lens containing the opticalfilter, unless indicated otherwise.

In some embodiments, an optical filter has absorbance peaks in each offour spectral bands, each of which has an attenuation factor greaterthan or equal to about 0.95. Because it is rare to observe monochromaticlight in the physical world, some narrow bands of light can be nearly orcompletely blocked out without significant detriment to the overallvariety of perceived spectral colors in the natural world. In otherwords, the optical filter can be employed in everyday vision without theloss of any substantial visual information.

In some embodiments, an optical filter has one or more absorbance peakswith a bandwidth that is at least partially within a chroma enhancementwindow. The width of the chroma enhancement window can be between about22 nm and about 45 nm, between about 20 nm and about 50 nm, greater thanor equal to about 20 nm, greater than or equal to about 15 nm, oranother suitable bandwidth range. In certain embodiments, an opticalfilter is configured such that every absorbance peak with an attenuationfactor greater than or equal to a threshold has a bandwidth within achroma enhancement window. For example, the bandwidth of each of theabsorbance peaks can be greater than or equal to about 10 nm, greaterthan or equal to about 15 nm, greater than or equal to about 20 nm,greater than or equal to about 22 nm, less than or equal to about 60 nm,less than or equal to about 50 nm, less than or equal to about 40 nm,between about 10 nm and about 60 nm, between about 20 nm and about 45nm, or between any of the other foregoing values.

Variations in the bandwidth (e.g., the FWHM value) and in the slopes ofthe sides of an absorbance peak can have marked effects on chroma.Generally, increases in the FWHM and/or slopes of the chroma-enhancingpeaks are accompanied by increases in chroma and vice-versa, in the caseof chroma-lowering peaks.

By controlling chroma according to the techniques disclosed herein, thechroma of one or more color bands can also be decreased in situationswhere less colorfulness in those color bands is desired. In someembodiments, an optical filter can be configured to decrease chroma inone or more color bands and increase chroma in other color bands. Forexample, eyewear designed for use while hunting ducks can include one ormore lenses with an optical filter configured to lower the chroma of ablue background and increase the chroma for green and brown feathers ofa duck in flight. More generally, an optical filter can be designed tobe activity-specific by providing relatively lower chroma in one or morespectral regions associated with a specific background (e.g., theground, the sky, an athletic field or court, a combination, etc.) andproviding relatively high chroma in one or more spectral regionsassociated with a specific foreground or object (e.g., a ball).Alternatively, an optical filter can have an activity-specificconfiguration by providing increased chroma in both a backgroundspectral region and an object spectral region.

The ability to identify and discern moving objects is generally called“Dynamic Visual Acuity.” An increase in chroma in the spectral region ofthe moving object is expected to improve this quality because increasesin chroma are generally associated with higher color contrast.Furthermore, the emphasis and de-emphasis of specific colors can furtherimprove Dynamic Visual Acuity. Various embodiments of optical filtersdescribed herein can be configured to increase Dynamic Visual Acuity inaddition to chroma. For example, an implementation of an optical filterconfigured to increase Dynamic Visual Acuity can provide high chroma inthe green to orange spectral region and relatively lower chroma in theblue spectral region.

In some embodiments, an optical filter is configured to account forvariation in luminous efficiency over the visible spectrum. Byaccounting for luminous efficiency, the filter can compensate fordifferences in relative sensitivities at different wavelengths of thehuman eye to various color bands can be compared. Luminous efficiencyover the visible spectrum, consistent with the Stockman and Sharpe conesensitivity data, is shown in FIG. 3.

In certain embodiments, an optical filter is configured to selectivelyincrease chroma in the red wavelengths at which the human eye is mostsensitive. For example, the red color band can be described as thespectral range extending between about 625 nm and about 700 nm. Whenlooking at the luminous efficiency function shown in FIG. 3, it isapparent that the eye is significantly more sensitive to red lightbetween about 625 nm and 660 nm than at longer wavelengths. Accordingly,an optical filter that is configured to increase chroma in redwavelengths can have an absorbance peak centered at wavelengths betweenabout 650 nm and 660 nm such that chroma is increased for redwavelengths over the red band up to 655 nm with an accompanying decreasein chroma for red above 660 nm, where the eye is less sensitive.

As another example, optical filters configured to increase chroma forwavelengths in the middle of the green range can have an absorbance peakcentered at about 553 nm, at about 561 nm, or at a wavelength betweenabout 550 nm and about 570 nm. Such a filter can also decrease chroma ofyellow colors, so it can be used in activities that benefit fromidentifying green objects that are viewed against a yellow background.

Various implementations of optical filters configured to increase chromain a plurality of spectral bands are described in U.S. Publication No.2013/0141693 which is incorporated herein by reference in its entirety.

A filter can include a chroma-enhancing window (CEW) that is configuredto enhance the chroma within a portion, substantially all, or the entirespectral window of a visual stimulus. An optical filter can provide oneor more edges of an absorptance peak within the spectral windows where astimulus is located. For example, the spectral location of a blue lightCEW can be selected to correspond to a particular fluorescent agent sothat eyewear can be spectrally matched to a particular fluorescentagent. Thus, eyewear and golf balls can be spectrally matched to provideenhanced golf ball visibility. Light at wavelengths below about 440 nmcan be attenuated so that potentially harmful short wavelength radiationdoes not enter the eye. For example, some of this short wavelengthradiation can be converted by the fluorescent agent to radiation atwavelengths corresponding to a blue light CEW. The average visible lighttransmittance of a golf lens can be about 20%-30% Filters for outdooruse typically have average transmittances between about 8%-80%, 10%-60%,or 10%-40%. Filters for indoor use (or use at illumination levels lowerthan normal daylight illumination) can have average transmittancesbetween about 20%-90%, 25%-80%, or 40%-60%.

Green grass and vegetation typically provide a reflected or emittedspectral stimulus with a light intensity maximum at a wavelength ofabout 550 nm. As mentioned above, wavelengths from about 500 nm to about600 nm can define a green or background spectral window. Without a greenlight CEW, light at wavelengths between 500 nm and 600 nm can have lowerchroma than desired, and vegetation can appear relatively muted, drab,or dark. As a result, the golfer's surroundings would appear unnaturaland the golfer's perception of vegetation would be impaired. Thisimpairment is especially serious with respect to putting because thegolfer generally tries to precisely determine various parameters of theputting surface, including height and thickness of the grass coveringthe putting surface, orientation of the blades of grass of the puttingsurface, and the surface topography. Because a golfer takes aboutone-half of her strokes at or near putting surfaces, any visualimpairments at putting surfaces are serious performance disadvantagesand are generally unacceptable. Misperception of vegetation is also asignificant disadvantage when playing out of a fairway or rough. A greenlight CEW, in combination with a blue light CEW, permits enhanced golfball visibility while permitting accurate assessment of backgroundsurfaces such as putting surfaces or other vegetation. An optical filtercan enhance the chroma of a desired object and background by exhibitingat least one edge of an absorptance peak within one or both of the greenlight CEW and the blue light CEW. The concurrence of at least one edgeof an absorptance peak within one or both of the green or blue spectralwindows further aids the human eye in distinguishing a golf ball fromits surroundings by enhancing the chroma of the ball, the chroma of thevegetation, or the chroma of both the ball and vegetation.

A red light CEW can extend over a wavelength range from about 610 nm toabout 720 nm, but the transmission of radiation at wavelengths beyondabout 700 nm provides only a small contribution to a viewed scenebecause of the low sensitivity of the human eye at these wavelengths. Ared light CEW can enhance the natural appearance of scenery viewed withan embodiment of an improved optical filter by enhancing the chroma ofat least some red light reflected by vegetation. In some embodiments, atleast one edge of the red absorptance peak (e.g., the absorptance peakbetween about 630 nm and about 660 nm) falls within the red light CEW.The more polychromatic light produced by enhancing the chroma of red,green, and blue components of light permits improved focus. In addition,convergence (pointing of the eyes to a common point) and focusing(accommodation) are interdependent, so that improved focusing permitsimproved convergence and improved depth perception. Providing CEWs inthe green and red portions of the visible spectrum can result inimproved depth perception as well as improved focus. A filter havingsuch CEWs can improve perception of vegetation (especially puttingsurfaces) and provide more natural looking scenery while retaining theenhanced golf ball visibility associated with the blue light CEW. Anoptical filter that provides at least one edge of an absorption peakwithin a CEW can enhance the quality of the light transmitted throughthe optical filter by increasing its chroma value.

Optical filters having CEWs covering one or more spectral ranges canprovide enhanced visibility. Optical filters having such a spectralprofile can be selected for a particular application based on ease offabrication or a desire for the optical filter to appear neutral. Forcosmetic reasons, it can be desirable to avoid eyewear that appearstinted to others.

Optical filters can be similarly configured for a variety of activitiesin which tracking and observation of an object against a background isfacilitated by wavelength-conversion. Such filters can include awavelength-conversion window, a background window, and a spectral-widthwindow. These CEWs are selected to enhance the chroma ofwavelength-converted light, light from activity-specific backgrounds,and light at additional wavelengths to further extend the total spectralwidth of chroma-enhanced light to improve focus, accommodation, orprovide more natural viewing. For application to a white golf ball asdescribed above, an optical filter is provided with a blue light CEWcorresponding to wavelength-conversion spectral components, a greenlight CEW to facilitate viewing of a background, and a red light CEW toimprove accommodation and the natural appearance of scenes. Such anoptical filter can have a substantially neutral color density. For otheractivities, particular CEWs can be chosen based on expected or measuredbackground colors and wavelengths produced by a wavelength-conversionprocess. For example, tennis is often played on a green playing surfacewith a yellow ball. Such a ball typically has a wavelength conversionregion that produces wavelength-converted light at wavelengths betweenabout 460 nm and 540 nm. An example filter for such an application has awavelength-conversion window at between about 460 nm to about 540 nm,and a background window centered at about 550 nm. Thewavelength-conversion window and the background window can have someoverlap. To provide more natural contrast and better focus, additionaltransmission windows can be provided in wavelength ranges of about 440nm to about 460 nm, from about 620 nm to about 700 nm, or in otherranges.

In alternative embodiments, an optical filter having an object-specificspectral window in addition to or instead of a wavelength-conversionwindow is provided. For example, for viewing of a golf ball that appearsred, the optical filter can include a red light CEW that enhances thechroma of red light to improve golf ball visibility. For natural,accurate viewing of backgrounds (such as putting surfaces), a greenlight CEW is also provided. If the golf ball also emits wavelengthconverted light, an additional wavelength-conversion window can beprovided, if desired. The filter can also include a spectral-widthwindow.

In some embodiments, an optical filter is configured to change thechroma values of a scene in one or more spectral regions in which anobject and/or a background reflect or emit light. An optical filter canbe configured to account for spectral regions where an object ofinterest and the background reflect or emit light. Absorptance peaks canbe positioned such that chroma is increased or decreased in one or morespectral regions where the object of interest is reflecting or emittinglight and where the background is reflecting or emitting light. Forexample, chroma enhancement within an object or a background spectralwindow can be obtained by configuring an optical filter such that atleast one edge of an absorptance peak is positioned within the spectralwindow.

An optical filter can increase contrast between the object and thebackground by providing chroma enhancement in one or both of the objectspectral window and the background spectral window. Color contrastimproves when chroma is increased. For example, when a white golf ballis viewed against a background of green grass or foliage at a distance,chroma enhancement technology can cause the green visual stimulus to bemore narrowband. A narrowed spectral stimulus causes the greenbackground to appear less washed out, resulting in greater colorcontrast between the golf ball and the background.

In order to fabricate the filter profiles shown above, a variety ofapproaches can be applied, such as through the use of dielectric stacks,multilayer interference coatings, rare earth oxide additives, organicdyes, or a combination of multiple polarization filters as described inU.S. Pat. No. 5,054,902, the entire contents of which are incorporatedby reference herein and made a part of this specification. Anothersuitable fabrication technique or a combination of techniques can alsobe used.

In certain embodiments, an optical filter includes one or more organicdyes that provide absorbance peaks with a relatively high attenuationfactor. For example, in some embodiments, a lens has an optical filterincorporating organic dyes supplied by Exciton of Dayton, Ohio. At leastsome organic dyes supplied by Exciton are named according to theapproximate center wavelength and/or peak location of their absorbancepeak. For example, ABS 407, ABS 473, ABS 574. ABS 647 nm and ABS 659dyes provide absorbance peaks at about 407 nm, 473 nm, 574 nm, 647 nmand 659 nm.

Other dyes for plastic exist that can also provide substantial increasesin chroma. For example, Crysta-Lyn Chemical Company of Binghamton, N.Y.offers DLS 402A dye, with an absorbance peak at 402 nm. In someembodiments, the DLS 402A dye can be used in place of the Exciton ABS407 dye. Crysta-Lyn also offers DLS 461B dye that provides an absorbancepeak at 461 nm. DLS 461B dye can be used in place of the Exciton ABS 473dye. Crysta-Lyn DLS 564B dye can be used in place of the Exciton ABS 574dye, while Crysta-Lyn DIS 654B dye can be used in place of Exciton ABS659 dye. In some embodiments, the dye can be incorporated into one ormore lens components, and the decision regarding which lens componentsinclude the dye can be based on properties, such as stability orperformance factors, of each specific dye.

In some embodiments, two or more dyes can be used to create a singleabsorbance peak or a plurality of absorbance peaks in close proximity toone another. For example, an absorbance peak with a center wavelengthand/or peak location positioned between about 555 nm and about 580 nmcan be creating using two dyes having center wavelengths and/or peaklocations at about 561 nm and 574 nm. In another embodiment, anabsorbance peak with a center wavelength and/or peak location positionedbetween about 555 nm and about 580 nm can be creating using two dyeshaving center wavelengths and/or peak locations at about 556 nm and 574nm. While each dye can individually produce an absorbance peak having aFWHM value of less than about 30 nm, when the dyes are used together inan optical filter, the absorbance peaks can combine to form a singleabsorbance peak with a bandwidth of about 45 nm or greater than or equalto about 40 nm.

In some embodiments, one or more of the dyes used in any filtercomposition disclosed herein can be replaced by one or more dyes havingsimilar spectral attributes. For example, if a dye, such as the ExcitonABS 473 dye, is not sufficiently stable to endure the lens formationprocess, one or more substitute dyes with improved stability and asimilar absorbance profile can be used, instead. Some lens formationprocesses, such as injection molding, can subject the lens and opticalfilter to high temperatures, high pressures, and/or chemically activematerials. Replacement dyes can be selected to have similar absorbanceprofiles of the dyes disclosed herein but improved stability orperformance. For example, a replacement dye can exhibit high stabilityduring injection molding of the lens or high stability under sunlight.

In some embodiments, a lens can include dyes or other materials that areselected or configured to increase the photostability of the chromaenhancing filter and other lens components. Any technique known in theart can be used to mitigate degradation of filter materials and/or otherlens components.

The relative quantities of any dye formulations disclosed herein can beadjusted to achieve a desired objective, such as, for example, a desiredoverall lens color, a chroma-enhancing filter having particularproperties, another objective, or a combination of objectives. Anoptical filter can be configured to have an absorbance profile with anycombination of the absorbance peaks disclosed herein and/or anycombination of other absorbance peaks in order to achieve desiredchroma-enhancing properties. The overall lens color can be selected suchthat it is similar to or the same as the stimulus of an object ofinterest or a background stimulus for a specific activity. By matchingthe color of the lens to an activity-specific stimulus, the contrast(such as, for example, color contrast) of the object of interest forthat activity can be increased.

Activity Specific Optical Filters

In certain embodiments, eyewear and optical filters provide one or moreCEWs corresponding to a specific activity. A filter can include one ormore CEWs in a portion of the visible spectrum in which an object ofinterest, such as, for example, a golf ball, emits or reflects asubstantial spectral stimulus. When referring to the spectral stimulusof an object of interest, a corresponding CEW can be referred to as theobject spectral window. When referring to spectral stimulus of abackground behind an object, a corresponding CEW can be referred to asthe background spectral window. Moreover, when referring to the spectralstimulus of the general surroundings, the spectral window can bereferred to as the surrounding spectral window. An optical filter can beconfigured such that one or more edges of an absorbance peak lie withinat least one spectral window. In this way, an optical filter can enhancechroma in the spectral ranges corresponding to a given spectral stimulus(e.g. object, background, or surroundings).

In such implementations, the optical filter is configured to enhanceobject visibility while preserving the natural appearance of viewedscenes. Such implementations of optical filters (and implementations ofeyewear that include such filters) can be configured for a wide range ofrecreational, sporting, professional, and other activities. For example,chroma-enhancing, enhanced-visibility filters can be provided foractivities that include viewing objects against water such as fishing,sailing, rowing, surfing, etc. As another example, chroma-enhancing,enhanced-visibility filters can be provided for activities that includeviewing objects against grass such as baseball, tennis, soccer, cricket,lacrosse, field hockey, etc. As another example, chroma-enhancing,enhanced-visibility filters can be provided for activities that includeviewing objects indoors in artificial illumination such as badminton,basketball, target shooting, racquetball, squash, table tennis, etc. Asanother example, chroma-enhancing, enhanced-visibility filters can beprovided for activities that include viewing objects against snow suchas skiing, ice hockey. As another example, chroma-enhancing,enhanced-visibility filters can be provided for activities that includeviewing objects outdoors in sunlight such as skiing, baseball, golf,shooting, hunting, soccer, etc.

Implementations of chroma-enhancing, enhanced-visibility filters thatare configured for activities that include viewing objects against aparticular background can have a common characteristic. For example,chroma-enhancing, enhanced-visibility filters that are provided foractivities that include viewing objects against water can be configuredto be polarizing to reduce glare resulting from light reflected from thewater. As another example, chroma-enhancing, enhanced-visibility filtersthat are provided for activities that include viewing objects againstwater can be configured to attenuate light in the blue and/or blue-greenspectral range to make objects stand-out against water. As anotherexample, chroma-enhancing, enhanced-visibility filters that are providedfor activities that include viewing objects against grass can beconfigured to attenuate light in the green spectral range to makeobjects stand-out against grass.

Specific activities can be grouped in more than one category. Forexample, baseball is played on grass as well as in different lightingconditions. Thus, optical filters can be further customized to provideenhanced visibility of the object under different conditions. Forexample, for sports such as golf, baseball and other racquet sports, theoptical filter can include an object chroma enhancement window selectedto increase the chroma of natural reflected light orwavelength-converted light produced by a fluorescent agent in abaseball, tennis ball, badminton birdie, or volleyball or light that ispreferentially reflected by these objects. Background windows andspectral-width windows can be provided so that backgrounds are apparent,scenes appear natural, and the wearer's focus and depth perception areimproved. For sports played on various surfaces, or in differentsettings such as tennis or volleyball, different background windows canbe provided for play on different surfaces. For example, tennis iscommonly played on grass courts or clay courts, and filters can beconfigured for each surface, if desired. As another example, ice hockeyis played on an icy surface that is provided with awavelength-conversion agent or colorant, and lenses can be configuredfor viewing a hockey puck with respect to such ice. Outdoor volleyballbenefits from accurate viewing of a volleyball against a blue sky, andthe background filter can be selected to permit accurate backgroundviewing while enhancing chroma in outdoor lighting. A differentconfiguration can be provided for indoor volleyball.

Eyewear that includes such filters can be activity-specific,surface-specific, or setting-specific. In addition, tinted eyewear canbe provided for activities other than sports in which it is desirable toidentify, locate, or track an object against backgrounds associated withthe activity. Some representative activities include dentistry, surgery,bird watching, fishing, or search and rescue operations. Such filterscan also be provided in additional configurations such as filters forstill and video cameras, or as viewing screens that are placed for theuse of spectators or other observers. Filters can be provided as lenses,unitary lenses, or as face shields. For example, a filter for hockey canbe included in a face shield.

Various embodiments of lenses including one or more filters that providecolor enhancement for certain example activities are described belowwith references to FIGS. 4A-8C. The one or more filters can includechroma enhancement dyes and/or color enhancing chromophores as describedin detail in this application, or coatings/thin film layers disposed ona substrate material, etc. In various embodiments, the one or morefilters can include dielectric stacks, multilayer interference coatings,rare earth oxide additives, organic dyes, or a combination of multiplepolarization filters as described in U.S. Pat. No. 5,054,902, the entirecontents of which are incorporated by reference herein and made a partof this specification. Some embodiments of interference coatings aresold by Oakley, Inc. of Foothill Ranch, Calif., U.S.A. under the brandname Iridium®. The example lens embodiments disclosed herein suitablefor use in other applications than those indicated when suchapplications involve environments with similar colors of interest. Theembodiments of the one or more filters for the sports activities areexamples, and it is understood that other suitable filters can be usedfor the exemplary activities described herein.

A. Filters to Provide Color Enhancement for Viewing Objects AgainstWater

Various embodiments of lenses used for viewing objects against waterpreferably reduce glare (e.g., glare resulting from sunlight reflectedfrom the surface of water). Reducing glare can advantageously increasethe ability of seeing objects on or below the surface of water. Forexample, reduce glare can allow a fisherman to view underwaterstructures and thus allow a fisherman to see fish underwater. Reducingglare can also allow a fisherman to see the fish bait. As anotherexample, reducing glare can allow a sailor to see buoys and othermarkers on the surface of water. Without subscribing to any particulartheory, sunlight reflected from the surface of the water is partiallypolarized, thus polarized lenses can be used to reduce glare.Accordingly, various embodiments of lenses used to view objects againsta backdrop including water can include light polarizing films and/orcoatings to filter out polarized light reflected from the surface of thewater. Various embodiments of lenses used view objects against abackdrop including water can also include filters that transmitdifferent colors in the visible spectral range with different values tocreate different viewing conditions. For example, some embodiments oflenses adapted to view objects against a backdrop including water cantransmit all colors of the visible spectrum such that there is littledistortion on bright sunny days. As another example, some embodiments oflenses adapted to view objects against a backdrop including water cantransmit colors in the yellow and red spectral ranges and attenuateand/or absorb colors in the blue and green spectral ranges. This canadvantageously allow objects under water and/or on the surface of thewater to be visible to the person. Various embodiments of lenses adaptedto view objects against a backdrop including water can also be tinted(e.g., grey, amber, brown or yellow) to increase visibility of objectsunder and/or on the surface of water, reduce eye strain and/or foraesthetic purpose. For example, various embodiments of lenses adapted toview objects against a backdrop including water can have a CIEchromaticity x value greater than 0.35 and a CIE chromaticity y valuegreater than 0.35.

FIGS. 4A-4C illustrate the effective spectral response of one or morefilters that can be included in an embodiment of a lens that is suitablefor viewing objects on the surface of water or underwater. FIG. 4Aillustrates the effective absorbance profile of an implementation of anoptical filter that can be included in an embodiment of a lens that issuitable for viewing objects on the surface of water or underwater.FIGS. 4B and 4C show the effective transmittance profile and therelative absorbance profile of the same implementation of the opticalfilter. The implementation of the optical filter is configured such thatthe effective transmittance profile through the one or more filters hasone or more “notches”. The presence of the notches in the transmittanceprofile creates distinct “pass-bands”. Wavelengths in each of thedistinct pass-bands are transmitted with lower attenuation thanwavelengths in the notches. The notches in the transmittance profile aredepicted as “peaks” in the corresponding absorbance profile depicted inFIG. 4A. For example, as observed from FIG. 4A, the effective absorbanceprofile of the optical filter implementation has a first peak betweenabout 460 nm and 495 nm and a second peak between about 560 nm and 590nm.

Referring to FIG. 4A, it is observed that the effective absorbanceprofile of the optical filter implementation included in an embodimentof a lens that is suitable for viewing objects on the surface of wateror underwater has a first “valley” in the wavelength range between about410 nm and about 460 nm; a second “valley” in the wavelength rangebetween about 500 nm and about 560 nm; and a third “valley” in thewavelength range between about 600 nm and about 700 nm. Wavelengths inthe first, second and third valleys have reduced absorbance as comparedto the wavelengths in the vicinity of the first and second peaks. Thevalleys in the absorbance profile correspond to the pass-bands in thetransmittance profile. It is noted from FIG. 4A that the first peak hasa full width at 80% maximum (FW80M) of about 15-30 nm around a centralwavelength of about 475 nm and the second peak has a FW80M of about10-20 nm around a central wavelength of about 575 nm.

It is observed from FIG. 4A that (i) the value of the optical densityfor wavelengths in the vicinity of the first peak around 475 nm is about40% higher as compared to the average value of the optical density forwavelengths in the first valley; and (ii) the value of the opticaldensity for wavelengths in the vicinity of the first peak around 475 nmis about 60% higher as compared to the average value of the opticaldensity for wavelengths in the second valley. Thus, wavelengths in thevicinity of the first peak around 475 nm are attenuated by about 40%more as compared to wavelengths in the vicinity of the first valley andby about 60% more as compared to wavelengths in the vicinity of thesecond valley.

It is further observed from FIG. 4A that (i) the value of the opticaldensity for wavelengths in the vicinity of the second peak around 575 nmis about 35% higher as compared to the average value of the opticaldensity for wavelengths in the second valley, and (ii) the value of theoptical density for wavelengths in the vicinity of the second peakaround 575 nm is about 120% higher as compared to the average value ofthe optical density for wavelengths in the third valley. Thus,wavelengths in the vicinity of the second peak around 575 nm areattenuated by about 35% more as compared to wavelengths in the vicinityof the second valley and by about 120% more as compared to wavelengthsin the vicinity of the third valley.

Accordingly, the optical filter implementation is configured toattenuate the wavelengths in the first peak by about 40% more on anaverage as compared to the wavelengths in the first valley and by about60% more on an average as compared to the wavelengths in the secondvalley. Similarly, the optical filter implementation is configured toattenuate the wavelengths in the second peak by about 35% more on anaverage as compared to the wavelengths in the second valley and by about120% more on an average as compared to the wavelengths in the thirdvalley. It is observed from FIG. 4A that the second peak has a narrowerbandwidth as compared to the first peak. Furthermore, the optical filterimplementation included in the embodiment of the lens suitable forviewing objects on the surface of water or underwater can be configuredto attenuate light having wavelengths less than 400 nm (e.g., in theultraviolet range). Thus, the embodiment of the lens suitable forsuitable for viewing objects on the surface of water or underwater canreduce the amount of ultraviolet light incident on a person's eyesthereby providing safety and health benefits. The attenuation factor ofthe absorbance peaks in the blue spectral region (e.g., between about440 nm and 490 nm) and green spectral region (e.g., between about 550 nmand about 590 nm) can be greater than or equal to about 0.8 and lessthan 1 in various implementations of optical filters adapted to viewobjects on the surface of water or underwater. Without any loss ofgenerality, the attenuation factor of an absorbance peak can be obtainedby dividing an integrated absorptance peak area within the spectralbandwidth by the spectral bandwidth of the absorbance peak.

The transmittance profile depicted in FIG. 4B corresponds to the sameoptical filter implementation whose absorbance profile is depicted inFIG. 4A. Accordingly, the effective transmittance profile of the opticalfilter implementation includes a first pass-band corresponding to firstvalley of the absorbance profile, a second pass-band corresponding tothe second valley of the absorbance profile and a third pass-bandcorresponding to the third valley absorbance profile. The first and thesecond pass-bands are separated by a first notch corresponding to thefirst peak of the absorbance profile. The second and the thirdpass-bands are separated by a second notch corresponding to the secondpeak of the absorbance profile.

It is observed from the transmittance profile that the first pass-bandis configured to transmit less than 10% of light in the violet-bluespectral ranges (e.g., between about 410 nm and about 460 nm); thesecond pass-band configured to transmit between about 10% and about 20%of the light in the green-yellow spectral ranges (e.g., between about500 nm and about 560 nm); and the third pass-band configured to transmitbetween about 20% and about 50% of the light in the orange-red spectralranges (e.g., between about 600 nm and about 700 nm). It is furtherobserved from FIG. 4B that the first and the second pass-bands have asubstantially flat-top such that substantially all the wavelengths ineach of the first and the second pass-bands are transmitted with almostequal intensity. Accordingly, the FW80M of the first pass-band is about40-50 nm and the FW80M of the second pass-band is about 70-80 nm. It isalso observed from FIG. 4B that the effective transmittance profile ofthe embodiment of the lens suitable for viewing objects on the surfaceof water or underwater can transmit between about 50% and about 80% oflight in the wavelength range between about 700 nm and about 790 nm.

FIG. 4C illustrates the effective relative absorbance profile of anembodiment of a lens including an optical filter that is suitable forviewing objects on the surface of water or underwater. The relativeabsorbance profile is obtained by plotting the term −log₁₀(%T_(λ)/τ_(v)) with respect to the wavelength (λ). The factor % T_(λ)represents the percentage of light transmitted through the one or morefilters at a wavelength λ and the factor τ_(v) represents luminoustransmittance as determined according to a technique defined in section5.6.1 the ANSI Z80.3-2009 specification for nonprescription sunglass andfashion eyewear requirements. It is observed that the relativeabsorption has a similar profile as the absorbance profile depicted inFIG. 4B. In various embodiments, the one or more filters are configuredsuch that the lens has a tint or chromaticity (e.g., grey, brown, amber,yellow, etc.) suitable for viewing objects on the surface of water orunderwater. For example, implementations of optical filters adapted toview objects on the surface of water or underwater can have a CIEchromaticity x value greater than or equal to about 0.35, greater thanor equal to about 0.38, greater than or equal to about 0.4 and/or lessthan or equal to about 0.5. As another example, implementations ofoptical filters suitable for shooting can have a CIE chromaticity xvalue greater than or equal to about 0.37, greater than or equal toabout 0.39, greater than or equal to about 0.42 and/or less than orequal to about 0.6.

Various embodiments of lenses including the one or more filters thatprovide color enhancement for viewing objects on the surface of water orunderwater as described above include polarization films or layers suchthat they are polarized to reduce glare. Various embodiments of lensesincluding the one or more filters that provide color enhancement forviewing objects against water as described above can include dielectricstacks, multilayer interference coatings, rare earth oxide additives,organic dyes, or a combination of multiple polarization filters asdescribed in U.S. Pat. No. 5,054,902, the entire contents of which areincorporated by reference herein and made a part of this specificationfor cosmetic purposes and/or to darken various embodiments of thelenses. Some embodiments of interference coatings are sold by Oakley,Inc. of Foothill Ranch, Calif., U.S.A under the brand name Iridium®.

B. Filters to Provide Color Enhancement for Baseball

Various embodiments of lenses used for baseball preferably allow theball player to spot the baseball in different lighting conditions (e.g.,bright lighting on sunny days, diffused lighting on cloudy days, spotlighting and flood lighting for playing at night, etc.). It would alsobe advantageous to include filters that make the baseball stand outagainst the sky and the grassy field in various embodiments of thelenses used for baseball. Additionally, various embodiments of thelenses used for baseball can include coatings, layers or films thatreduce glare (e.g., glare resulting from sunlight on bright sunny daysor spot lights and flood light in the night). The coatings, layers orfilms that reduce glare can include polarizing films and/or coatings tofilter out polarized light, holographic or diffractive elements that areconfigured to reduce glare and/or diffusing elements. Variousembodiments of lenses suitable for baseball can include implementationsof optical filter that transmit different colors in the visible spectralrange with different values to create different viewing conditions. Forexample, some embodiments of lenses for baseball can transmit all colorsof the visible spectrum such that there is little distortion on brightsunny days. As another example, some embodiments of lenses for baseballcan transmit colors in the yellow and red spectral ranges and attenuateand/or absorb colors in the blue and green spectral ranges such that thebaseball can stand-out against the blue sky or the green grass. Variousembodiments of lenses used for baseball can also be tinted (e.g., grey,green, amber, brown or yellow) to increase visibility of baseballagainst the sky or the grass, reduce eye strain and/or for aestheticpurpose.

FIGS. 5A-5C illustrate the effective spectral response ofimplementations of optical filters that can be included in variousembodiments of lenses suitable for baseball. FIG. 5A illustrates twoeffective absorbance profiles of implementations of optical filters thatcan be included in various embodiments of lenses suitable for baseball.The first effective absorbance profile represented by a solid linerepresents the effective absorbance profile of an optical filterimplementation that can be included in an embodiment of a lens that issuitable for players in the outfield. The second effective absorbanceprofile represented by a dashed line represents the effective absorbanceprofile of an optical filter implementation that can be included in anembodiment of a lens that is suitable for players in the infield. FIG.5B illustrates two effective transmittance profiles of the same opticalfilter implementations that can be included in various embodiments oflenses suitable for baseball. The first effective transmittance profilerepresented by a solid line represents the effective transmittanceprofile of the same optical filter implementation that can be includedin an embodiment of a lens that is suitable for players in the outfield.The second effective transmittance profile represented by a dashed linerepresents the effective transmittance profile of the same opticalfilter implementation that can be included in an embodiment of a lensthat is suitable for players in the infield. FIG. 5C illustrates twoeffective relative absorbance profiles of the same optical filterimplementation that can be included in various embodiments of lensessuitable for baseball. The first relative absorbance profile representedby a solid line represents the effective relative absorbance profile ofthe same optical filter implementation that can be included in anembodiment of a lens that is suitable for players in the outfield. Thesecond effective relative absorbance profile represented by a dashedline represents the effective relative absorbance profile of the sameoptical filter implementation that can be included in an embodiment of alens that is suitable for players in the infield.

The outfield players and infield players play under different lightingconditions and thus would benefit from having lenses tailored to spotthe baseball in their respective lighting conditions. Additionally, itwould be advantageous for outfield players to have the ability to spotthe baseball from a distance. Thus, it would be beneficial if variousembodiments of lenses are configured to have different opticalcharacteristics for infield players and outfield players. For example,since the outfield is usually sunnier than the infield and/or has lessshadows as compared to the infield, it would be advantageous if thelenses configured for the players in the outfield included filters thatreduced glare and overall brightness but transmitted different colors inthe visible spectral range so that the white baseball can be spottedfrom a distance. As another example, it would be advantageous if thelenses configured for the players in the infield included filters thatreduced glare, increased contrast between the blue sky and the greengrass and in general made the white ball and the red stitching on thebaseball stand-out against the field.

As discussed above, the effective absorbance profile depicted in FIG. 5Aexhibits peaks and valleys that correspond to the pass-bands and notchesexhibited by the corresponding effective transmittance profile depictedin FIG. 5B.

Referring to FIG. 5A, the effective absorbance profiles for the opticalfilter implementations included in embodiments of lenses suitable forplayers in the outfield and players in the infield each has a first peakbetween about 460 nm and 490 nm, a second peak between about 560 nm and590 nm and a third peak between about 640 nm and 680 nm. The effectiveabsorbance profile for the optical filter implementation included inembodiments of lenses suitable for players in the outfield and playersin the infield each has a first valley in the wavelength range betweenabout 410 nm and about 460 nm; a second valley in the wavelength rangebetween about 500 nm and about 560 nm; and a third valley in thewavelength range between about 590 nm and about 640 nm. As discussedabove, wavelengths in the first, second and third valleys have reducedabsorbance as compared to the wavelengths in the vicinity of the first,second and third peaks.

Referring to the effective absorbance profile, depicted in FIG. 5A, forthe optical filter implementation included in embodiments of lensessuitable for players in the outfield represented by the solid line, itis observed that the first peak has a full width at half maximum (FWHM)of about 25-30 nm around a central wavelength of about 475 nm, thesecond peak has a FW80M of about 10-15 nm around a central wavelength ofabout 575 nm and the third peak has a FWHM of about 20-25 nm around acentral wavelength of about 660 nm.

Referring to the effective absorbance profile, depicted in FIG. 5A, forthe optical filter implementations included in embodiments of lensessuitable for players in the outfield represented by the solid line, itis observed that (i) the value of the optical density for wavelengths inthe vicinity of the first peak around 475 nm is about 300% higher ascompared to the average value of the optical density for wavelengths inthe first valley; (ii) the value of the optical density for wavelengthsin the vicinity of the first peak around 475 nm is about 200% higher ascompared to the average value of the optical density for wavelengths inthe second valley. Thus, wavelengths in the vicinity of the first peakaround 475 nm are attenuated by about 300% more as compared towavelengths in the vicinity of the first valley and by about 200% moreas compared to wavelengths in the vicinity of the second valley.

Referring to the effective absorbance profile, depicted in FIG. 5A, forthe optical filter implementations included in embodiments of lensessuitable for players in the outfield represented by the solid line, itis observed that (i) the value of the optical density for wavelengths inthe vicinity of the second peak around 575 nm is about 100% higher ascompared to the average value of the optical density for wavelengths inthe second valley, and (ii) the value of the optical density forwavelengths in the vicinity of the second peak around 575 nm is about150% higher as compared to the average value of the optical density forwavelengths in the third valley. Thus, wavelengths in the vicinity ofthe second peak around 575 nm are attenuated by about 100% more ascompared to wavelengths in the vicinity of the second valley and byabout 150% more as compared to wavelengths in the vicinity of the thirdvalley.

Referring to the effective absorbance profile, depicted in FIG. 5A, forthe optical filter implementations included in embodiments of lensessuitable for players in the outfield represented by the solid line, itis observed that (i) the value of the optical density for wavelengths inthe vicinity of the third peak around 660 nm is about 400% higher ascompared to the average value of the optical density for wavelengths inthe third valley. Thus, wavelengths in the vicinity of the third peakaround 660 nm are attenuated by about 400% more as compared towavelengths in the vicinity of the third valley.

Referring to the effective absorbance profile, depicted in FIG. 5A, forthe optical filter implementations included in embodiments of lensessuitable for players in the infield represented by the dashed line, itis observed that the first peak has a full width at half maximum (FWHM)of about 25-30 nm around a central wavelength of about 475 nm, thesecond peak has a full width at 90% maximum (FW90M) of about 10-15 nmaround a central wavelength of about 575 nm and the third peak has aFWHM of about 20-25 nm around a central wavelength of about 660 nm.

Referring to the effective absorbance profile, depicted in FIG. 5A, forthe optical filter implementations included in embodiments of lensessuitable for players in the infield represented by the dashed line, itis observed that (i) the value of the optical density for wavelengths inthe vicinity of the first peak around 475 nm is about 320% higher ascompared to the average value of the optical density for wavelengths inthe first valley; (ii) the value of the optical density for wavelengthsin the vicinity of the first peak around 475 nm is about 320% higher ascompared to the average value of the optical density for wavelengths inthe second valley. Thus, wavelengths in the vicinity of the first peakaround 475 nm are attenuated by about 320% more as compared towavelengths in the vicinity of the first and the second valley.

Referring to the effective absorbance profile, depicted in FIG. 5A, forthe optical filter implementations included in embodiments of lensessuitable for players in the infield represented by the dashed line, itis observed that (i) the value of the optical density for wavelengths inthe vicinity of the second peak around 575 nm is about 50% higher ascompared to the average value of the optical density for wavelengths inthe second valley; and (ii) the value of the optical density forwavelengths in the vicinity of the second peak around 575 nm is about100% higher as compared to the average value of the optical density forwavelengths in the third valley. Thus, wavelengths in the vicinity ofthe second peak around 575 nm are attenuated by about 50% more ascompared to wavelengths in the vicinity of the second valley and byabout 100% more as compared to wavelengths in the vicinity of the thirdvalley.

Referring to the effective absorbance profile, depicted in FIG. 5A, forthe optical filter implementations included in embodiments of lensessuitable for players in the infield represented by the dashed line, itis observed that (i) the value of the optical density for wavelengths inthe vicinity of the third peak around 660 nm is about 320% higher ascompared to the average value of the optical density for wavelengths inthe third valley. Thus, wavelengths in the vicinity of the third peakaround 660 nm are attenuated by about 320% more as compared towavelengths in the vicinity of the third valley.

Furthermore, the one or more filters included in the embodiment of thelens suitable for baseball players in the outfield and baseball playerin the infield can be configured to attenuate light having wavelengthsless than 400 nm (e.g., in the ultraviolet range). Thus, the embodimentof the lens suitable for baseball players in the outfield and baseballplayer in the infield can reduce the amount of ultraviolet lightincident on the player's eyes thereby providing safety and healthbenefits.

Comparing the effective absorbance profiles of the implementations ofoptical filters configured for use by baseball players in the outfieldand baseball players in the infield, it is noted that the optical filterimplementation configured for use by baseball players in the infieldabsorb wavelengths around 475 nm (e.g., blue light) to a greater extentas compared to the optical filter implementations configured for use bybaseball players in the outfield and absorb wavelengths around 575 nm(e.g., greenish-yellow light) and 660 nm (e.g., red light) to a lesserextent as compared to the optical filter implementations configured foruse by baseball players in the outfield.

The attenuation factor of the absorbance peaks in the blue spectralregion (e.g., between 440 nm and 490 nm) and red spectral region (e.g.,between 620 nm and 670 nm) can be greater than or equal to about 0.8 andless than 1 in various implementations of optical filters configured foruse by baseball players in the outfield and/or infield. Without any lossof generality, the attenuation factor of an absorbance peak can beobtained by dividing an integrated absorptance peak area within thespectral bandwidth by the spectral bandwidth of the absorbance peak.

As discussed above, the peaks in the effective absorbance profilecorresponds to notches in the effective transmittance profile. Thepresence of notches in the effective transmittance profile createsdistinct pass-bands. Wavelengths in each of the distinct pass-bands aretransmitted with lower attenuation than wavelengths in the notches. Inthe illustrated transmission spectra in FIG. 5B, the effectivetransmittance profile of the optical filter implementations in anembodiment of the lens suitable for outfield players (represented bysolid line) has a first pass-band configured to transmit between about1% to about 40% of light in the violet-blue spectral ranges (e.g.,between about 410 nm and about 460 nm); a second pass-band configured totransmit between about 1% and about 15% of the light in the green-yellowspectral ranges (e.g., between about 500 nm and about 560 nm); and athird pass-band configured to transmit between about 5% and about 40% ofthe light in the orange-red spectral ranges (e.g., between about 590 nmand about 640 nm).

In the illustrated transmittance profile in FIG. 5B, the effectivetransmittance profile of the optical filter implementations in anembodiment of the lens suitable for infield players (represented bydashed line) has a first pass-band configured to transmit between about1% to about 30% of light in the violet-blue spectral ranges (e.g.,between about 410 nm and about 460 nm), a second pass-band configured totransmit between about 1% and about 20% of the light in the green-yellowspectral ranges (e.g., between about 500 nm and about 560 nm); and athird pass-band configured to transmit between about 5% and about 30% ofthe light in the orange-red spectral ranges (e.g., between about 590 nmand about 640 nm).

Comparing the embodiments of the lenses for outfield players and infieldplayers, it is noted that embodiments of lenses for outfield players areconfigured to transmit more light in the violet-blue spectral range andthe orange-red spectral range as compared to embodiments of lenses forinfield players. It is also noted that embodiments of lenses foroutfield players are configured to transmit less light in thegreen-yellow spectral range as compared to embodiments of lenses forinfield players.

It is further observed from FIG. 5B, that the second pass-band forembodiments of lenses for outfield and infield players has asubstantially flat-top such that substantially all the wavelengths inthe second pass-band are transmitted with almost equal intensity. Incontrast, the first and third pass-bands for embodiments of lenses foroutfield and infield players have a bell-shaped profile. It is observedfrom FIG. 5B that the FWHM of the first pass-band for embodiments oflenses for outfield players is about 30 nm around a central wavelengthof about 425 nm; the FWHM of the second pass-band for embodiments oflenses for outfield players is about 80-90 nm around a centralwavelength of about 530 nm; and the FWHM of the third pass-band forembodiments of lenses for outfield players is about 40 nm around acentral wavelength of about 620 nm. It is further observed from FIG. 5Bthat the FWHM of the first pass-band for embodiments of lenses forinfield players is about 25-35 nm around a central wavelength of about420 nm; the FWHM of the second pass-band for embodiments of lenses forinfield players is about 80-90 nm around a central wavelength of about540 nm; and the FW90M of the third pass-band for embodiments of lensesfor infield players is about 20 nm around a central wavelength of about620 nm.

It is also observed from FIG. 5B that the effective transmittanceprofile for embodiments of lenses for outfield and infield players cantransmit between about 80% and about 90% of light in the wavelengthrange between about 680 nm and about 790 nm.

FIG. 5C illustrates two effective relative absorption spectra of opticalfilter implementations that can be included in various embodiments oflenses suitable for baseball. The first effective relative absorbanceprofile represented by a solid line represents the effective relativeabsorbance profile of an implementation of an optical filter that can beincluded in an embodiment of a lens that is suitable for players in theoutfield. The second effective relative absorbance profile representedby a dashed line represents the effective relative absorbance profile ofan implementation of an optical filter that can be included in anembodiment of a lens that is suitable for players in the infield. Asdiscussed above, the relative absorbance profile is obtained by plottingthe term −log₁₀(% T_(λ)/τ_(v)) with respect to the wavelength (λ). Thefactor % T_(λ) represents the percentage of light transmitted throughthe one or more filters at a wavelength λ and the factor τ_(v)represents luminous transmittance as determined according to a techniquedefined in section 5.6.1 the ANSI Z80.3-2009 specification fornonprescription sunglass and fashion eyewear requirements. It isobserved from FIG. 5C that each of the relative absorbance profile has asimilar profile as the corresponding absorbance profile depicted in FIG.5A. As discussed above, in various embodiments the one or more filterscan also be configured to provide tint or chromaticity (e.g., grey,brown, amber, yellow, etc.) to the lens embodiments that are suitablefor infield and/or outfield players. For example, variousimplementations of lenses including implementations of optical filtersthat can be used for playing baseball can have a CIE chromaticity xvalue greater than or equal to about 0.35, greater than or equal toabout 0.38, greater than or equal to about 0.4 and/or less than or equalto about 0.5. As another example, implementations of optical filterssuitable for shooting can have a CIE chromaticity x value greater thanor equal to about 0.37, greater than or equal to about 0.39, greaterthan or equal to about 0.42 and/or less than or equal to about 0.6.

As discussed above, the one or more embodiments that are suitable forinfield and/or outfield players can include dielectric stacks,multilayer interference coatings, rare earth oxide additives, organicdyes, or a combination of multiple polarization filters as described inU.S. Pat. No. 5,054,902, the entire contents of which are incorporatedby reference herein and made a part of this specification for cosmeticpurposes and/or to darken various embodiments of the lenses. Someembodiments of interference coatings are sold by Oakley, Inc. ofFoothill Ranch, Calif., U.S.A. under the brand name Iridium®.

C. Filters to Provide Color Enhancement for Snow Sports

Various embodiments of lenses used for viewing objects against snow orengaging in snow sports (e.g., skiing, snowboarding, sledding, snowshoeing etc.) preferably reduce glare (e.g., glare resulting fromsunlight reflected from the snow). Reducing glare can advantageouslyincrease the ability of seeing objects on the surface of the slope andthereby allow a snow sportsman to perform to the best of his/herability. Accordingly, various embodiments of lenses used for snow sportscan include coatings, layers or films that reduce glare. The glarereducing coatings, layers or films can include polarizing films and/orcoatings to filter out polarized light, holographic or diffractiveelements that are configured to reduce glare and/or diffusing elements.Additionally, it would be advantageous for various embodiments of lensesused for snow sports to include filters that make trees, sky and otherobjects (e.g., stones, boulders, tree roots, etc.) stand-out from thesnow to enhance the experience of the snow sportsman. Making trees, skyand other objects (e.g., stones, boulders, tree roots, etc.) stand-outfrom the snow can also allow the snow sportsman to safely engage in thesporting activity of his/her choice. Additionally, since the lightingconditions can change on the slope, it would be advantageous to tailordifferent embodiments of lenses for different lighting conditions. Forexample, some embodiments of lenses for snow sports can be configuredfor viewing in bright light, such as on bright sunny days. As anotherexample, some embodiments of lenses for snow sports can be configuredfor viewing in low light, such as on cloudy days. As yet anotherexample, some embodiments of lenses for snow sports can be configuredfor viewing in bright as well as low light. Various embodiments oflenses suitable for snow sports can include one or more filters thattransmit different colors in the visible spectral range with differentvalues to create different viewing conditions. For example, someembodiments of lenses for snow sports can transmit all colors of thevisible spectrum such that there is little distortion on bright sunnydays. As another example, some embodiments of lenses for snow sports cantransmit colors in the yellow and red spectral ranges and attenuateand/or absorb colors in the blue and green spectral ranges. Variousembodiments of lenses used for snow sports can also be tinted (e.g.,grey, green, amber, brown or yellow) to increase contrast between thesnow and the sky and/or trees, reduce eye strain and/or for aestheticpurpose.

FIGS. 6A-6C illustrate the effective spectral response ofimplementations of optical filters that can be included in variousembodiments of lenses suitable for snow sports. FIG. 6A illustratesthree effective absorbance profiles of implementations of opticalfilters that can be included in various embodiments of lenses suitablefor snow sports. The first effective absorbance profile represented by asolid line represents the effective absorbance profile of an opticalfilter implementation that can be included in an embodiment of a lensthat is suitable for engaging in snow sports in low light. The secondeffective absorbance profile represented by a dashed line represents theeffective absorbance profile of an optical filter implementation thatcan be included in an embodiment of a lens that is suitable for engagingin snow sports in bright light. The third effective absorbance profilerepresented by a dash-dot line represents the effective absorbanceprofile of an optical filter implementation that can be included in anembodiment of a lens that is suitable for engaging in snow sports inbright and/or low light.

FIG. 6B illustrates three effective transmittance profiles of an opticalfilter implementation that can be included in various embodiments oflenses suitable for snow sports. The first effective transmittanceprofile represented by a solid line represents the effectivetransmittance profile of an optical filter implementation that can beincluded in an embodiment of a lens that is suitable for engaging insnow sports in low light. The second effective transmittance profilerepresented by a dashed line represents the effective transmittanceprofile of an optical filter implementation that can be included in anembodiment of a lens that is suitable for engaging in snow sports inbright light. The third effective transmittance profile represented by adash-dot line represents the effective transmittance profile of anoptical filter implementation that can be included in an embodiment of alens that is suitable for engaging in snow sports in bright and/or lowlight.

FIG. 6C illustrates three effective relative absorbance profiles ofimplementations of optical filters that can be included in variousembodiments of lenses suitable for snow sports. The first effectiverelative absorbance profile represented by a solid line represents theeffective relative absorbance of an optical filter implementation thatcan be included in an embodiment of a lens that is suitable for engagingin snow sports in low light. The second effective relative absorbanceprofile represented by a dashed line represents the effective relativeabsorbance profile of an optical filter implementation that can beincluded in an embodiment of a lens that is suitable for engaging insnow sports in bright light. The third effective relative absorbanceprofile represented by a dash-dot line represents the effective relativeabsorbance profile of an optical filter implementation that can beincluded in an embodiment of a lens that is suitable for engaging insnow sports in bright and/or low light.

As discussed above, the effective absorbance profile depicted in FIG. 6Aexhibits peaks and valleys that correspond to the pass-bands and notchesexhibited by the corresponding effective transmittance profile depictedin FIG. 6B.

Referring to FIG. 6A, the effective absorbance profiles for theimplementations of optical filters included in embodiments of lensessuitable for engaging in snow sports in different lighting conditionseach has a first peak between about 460 nm and 490 nm, a second peakbetween about 560 nm and 590 nm and a third peak between about 640 nmand 680 nm. The effective absorbance profile for the optical filterimplementations included in embodiments of lenses suitable for engagingin snow sports in different lighting conditions each has a first valleyin the wavelength range between about 410 nm and about 460 nm; a secondvalley in the wavelength range between about 500 nm and about 560 nm;and a third valley in the wavelength range between about 590 nm andabout 640 nm. As discussed above, wavelengths in the first, second andthird valleys have reduced absorbance as compared to the wavelengths inthe vicinity of the first, second and third peaks.

Referring to the effective absorbance profile, depicted FIG. 6A, for theoptical filter implementations included in embodiments of lensessuitable for engaging in snow sports in low light represented by thesolid line, it is observed that the first peak has a full width at halfmaximum (FWHM) of about 25-30 nm around a central wavelength of about475 nm, the second peak has a FW90M of about 10-15 nm around a centralwavelength of about 575 nm and the third peak has a FW80M of about 25-30nm around a central wavelength of about 660 nm.

Referring to the effective absorbance profile, depicted in FIG. 6A, forthe optical filter implementations included in embodiments of lensessuitable for engaging in snow sports in low light represented by thesolid line, it is observed that (i) the value of the optical density forwavelengths in the vicinity of the first peak around 475 nm is about400% higher as compared to the average value of the optical density forwavelengths in the first valley; (ii) the value of the optical densityfor wavelengths in the vicinity of the first peak around 475 nm is about250% higher as compared to the average value of the optical density forwavelengths in the second valley. Thus, wavelengths in the vicinity ofthe first peak around 475 nm are attenuated by about 4000 more ascompared to wavelengths in the vicinity of the first valley and by about250% more as compared to wavelengths in the vicinity of the secondvalley.

Referring to the effective absorbance profile, depicted in FIG. 6A, forthe optical filter implementations included in embodiments of lenses forengaging in snow sports in low light represented by the solid line, itis observed that (i) the value of the optical density for wavelengths inthe vicinity of the second peak around 575 nm is about 0-10% higher ascompared to the average value of the optical density for wavelengths inthe second valley; and (ii) the value of the optical density forwavelengths in the vicinity of the second peak around 575 nm is about350% higher as compared to the average value of the optical density forwavelengths in the third valley. Thus, wavelengths in the vicinity ofthe second peak around 575 nm are attenuated by about 0-10% more ascompared to wavelengths in the vicinity of the second valley and byabout 350% more as compared to wavelengths in the vicinity of the thirdvalley.

Referring to the effective absorbance profile, depicted in FIG. 6A, forthe optical filter implementations included in embodiments of lensessuitable for engaging in snow sports in low light represented by thesolid line, it is observed that (i) the value of the optical density forwavelengths in the vicinity of the third peak around 660 nm is about100% higher as compared to the average value of the optical density forwavelengths in the third valley. Thus, wavelengths in the vicinity ofthe third peak around 660 nm are attenuated by about 100% more ascompared to wavelengths in the vicinity of the third valley.

Referring to the effective absorbance profile, depicted in FIG. 6A, forthe optical filter implementations included in embodiments of lensessuitable for engaging in snow sports in bright light represented by thedashed line, it is observed that the first peak has a full width at halfmaximum (FWHM) of about 25-35 nm around a central wavelength of about475 nm, the second peak has a FW90M of about 10-15 nm around a centralwavelength of about 575 nm and the third peak has a FW80M of about 25-30nm around a central wavelength of about 660 nm.

Referring to the effective absorbance profile, depicted in FIG. 6A, forthe optical filter implementations included in embodiments of lensessuitable for engaging in snow sports in bright light represented by thedashed line, it is observed that (i) the value of the optical densityfor wavelengths in the vicinity of the first peak around 475 nm is about200% higher as compared to the average value of the optical density forwavelengths in the first valley; (ii) the value of the optical densityfor wavelengths in the vicinity of the first peak around 475 nm is about140% higher as compared to the average value of the optical density forwavelengths in the second valley. Thus, wavelengths in the vicinity ofthe first peak around 475 nm are attenuated by about 200% more ascompared to wavelengths in the vicinity of the first valley and by about140% more as compared to wavelengths in the vicinity of the secondvalley.

Referring to the effective absorbance profile, depicted in FIG. 6A, forthe optical filter implementations included in embodiments of lenses forengaging in snow sports in bright light represented by the dashed line,it is observed that (i) the value of the optical density for wavelengthsin the vicinity of the second peak around 575 nm is about 20-25% higheras compared to the average value of the optical density for wavelengthsin the second valley; and (ii) the value of the optical density forwavelengths in the vicinity of the second peak around 575 nm is about100% higher as compared to the average value of the optical density forwavelengths in the third valley. Thus, wavelengths in the vicinity ofthe second peak around 575 nm are attenuated by about 20-25% more ascompared to wavelengths in the vicinity of the second valley and byabout 100% more as compared to wavelengths in the vicinity of the thirdvalley.

Referring to the effective absorbance profile, depicted in FIG. 6A, forthe optical filter implementations included in embodiments of lensessuitable for engaging in snow sports in bright light represented by thedashed line, it is observed that (i) the value of the optical densityfor wavelengths in the vicinity of the third peak around 660 nm is about100% higher as compared to the average value of the optical density forwavelengths in the third valley. Thus, wavelengths in the vicinity ofthe third peak around 660 nm are attenuated by about 100% more ascompared to wavelengths in the vicinity of the third valley.

Referring to the effective absorbance profile, depicted in FIG. 6A, forthe optical filter implementations included in embodiments of lensessuitable for engaging in snow sports in bright and/or low lightrepresented by the dash-dot line, it is observed that the first peak hasa full width at half maximum (FWHM) of about 25-35 nm around a centralwavelength of about 475 nm, the second peak has a FW90M of about 10-15nm around a central wavelength of about 575 nm and the third peak has aFW80M of about 25-30 nm around a central wavelength of about 660 nm.

Referring to the effective absorbance profile, depicted in FIG. 6A, forthe optical filter implementations included in embodiments of lensessuitable for engaging in snow sports in bright and/or low lightrepresented by the dash-dot line, it is observed that (i) the value ofthe optical density for wavelengths in the vicinity of the first peakaround 475 nm is about 350% higher as compared to the average value ofthe optical density for wavelengths in the first valley; (ii) the valueof the optical density for wavelengths in the vicinity of the first peakaround 475 nm is about 200% higher as compared to the average value ofthe optical density for wavelengths in the second valley. Thus,wavelengths in the vicinity of the first peak around 475 nm areattenuated by about 350% more as compared to wavelengths in the vicinityof the first valley and by about 200% more as compared to wavelengths inthe vicinity of the second valley.

Referring to the effective absorbance profile, depicted in FIG. 6A, forthe optical filter implementations included in embodiments of lenses forengaging in snow sports in bright and/or low light represented by thedash-dot line, it is observed that (i) the value of the optical densityfor wavelengths in the vicinity of the second peak around 575 nm isabout 0-10% higher as compared to the average value of the opticaldensity for wavelengths in the second valley; and (ii) the value of theoptical density for wavelengths in the vicinity of the second peakaround 575 nm is about 100% higher as compared to the average value ofthe optical density for wavelengths in the third valley. Thus,wavelengths in the vicinity of the second peak around 575 nm areattenuated by about 0-10% more as compared to wavelengths in thevicinity of the second valley and by about 100% more as compared towavelengths in the vicinity of the third valley.

Referring to the effective absorbance profile, depicted in FIG. 6A, forthe optical filter implementations included in embodiments of lensessuitable for engaging in snow sports in bright and/or low lightrepresented by the dash-dot line, it is observed that (i) the value ofthe optical density for wavelengths in the vicinity of the third peakaround 660 nm is about 20% higher as compared to the average value ofthe optical density for wavelengths in the third valley. Thus,wavelengths in the vicinity of the third peak around 660 nm areattenuated by about 20% more as compared to wavelengths in the vicinityof the third valley.

Furthermore, the optical filter implementations included in theembodiment of the lens suitable for engaging in snow sports in differentlighting conditions can be configured to attenuate light havingwavelengths less than 400 nm (e.g., in the ultraviolet range). Thus, theembodiment of the lens suitable for engaging in snow sports in differentlighting conditions can reduce the amount of ultraviolet light incidenton the player's eyes thereby providing safety and health benefits.

Comparing the effective absorbance profiles of optical filterimplementations configured for engaging in snow sports in differentlighting conditions, it is noted that the one or more filters configuredfor use in low light absorb wavelengths around 475 nm (e.g., bluelight), wavelengths around 575 nm (e.g., yellow-green light) andwavelengths around 660 nm (e.g., red light) to a lesser extent ascompared to the one or more filters configured for use in bright lineand bright and/or low light. It is further noted that the optical filterimplementations configured for use in bright and/or low light absorbwavelengths around 475 nm (e.g., blue light) to a greater extent ascompared to the one or more filters configured for use in bright lightand absorb wavelengths around 575 nm (e.g., greenish-yellow light) and660 nm (e.g., red light) to a lesser extent as compared to the one ormore filters configured for use in bright light.

The attenuation factor of the absorbance peaks in the blue spectralregions (e.g., between about 450 nm and about 490 nm) and green spectralregion (e.g., between about 550 nm and about 590 nm) can be greater thanor equal to about 0.8 and less than 1 in various implementations ofoptical filters adapted to view objects against snow. The attenuationfactor of the absorbance peaks in the red spectral region (e.g., betweenabout 630 nm and about 670 m) can be between about 0.5 and 0.8 invarious implementations of optical filters adapted to view objectsagainst snow.

As discussed above, the peaks in the effective absorbance profilecorresponds to notches in the effective transmittance profile. Thepresence of notches in the effective transmittance profile createsdistinct pass-bands. Wavelengths in each of the distinct pass-bands aretransmitted with lower attenuation than wavelengths in the notches. Inthe transmittance profiles illustrated in FIG. 6B, the effectivetransmittance profile of the implementation of optical filter in anembodiment of the lens suitable for engaging in snow sports in low light(represented by solid line) has a first pass-band configured to transmitbetween about 1% to about 40% of light in the violet-blue spectralranges (e.g., between about 410 nm and about 460 nm); a second pass-bandconfigured to transmit between about 1% and about 20% of the light inthe green-yellow spectral ranges (e.g., between about 490 nm and about560 nm), and a third pass-band configured to transmit between about 10%and about 75% of the light in the orange-red spectral ranges (e.g.,between about 590 nm and about 650 nm).

In the transmittance profiles illustrated in FIG. 6B, the effectivetransmittance profile of the implementation of optical filter includedin an embodiment of the lens suitable for engaging in snow sports inbright light (represented by dashed line) has a first pass-bandconfigured to transmit between about 1% to about 10° % of light in theviolet-blue spectral ranges (e.g., between about 405 nm and about 460nm); a second pass-band configured to transmit between about 1% andabout 5% of the light in the green-yellow spectral ranges (e.g., betweenabout 490 nm and about 570 nm); and a third pass-band configured totransmit between about 5% and about 20% of the light in the orange-redspectral ranges (e.g., between about 580 nm and about 650 nm).

In the transmittance profiles illustrated in FIG. 6B, the effectivetransmittance profile of the implementation of optical filter includedin an embodiment of the lens suitable for engaging in snow sports inbright and/or low light (represented by dash-dot line) has a firstpass-band configured to transmit between about 1% to about 20% of lightin the violet-blue spectral ranges (e.g., between about 405 nm and about460 nm); a second pass-band configured to transmit between about 1% andabout 10% of the light in the green-yellow spectral ranges (e.g.,between about 490 nm and about 570 nm); and a third pass-band configuredto transmit between about 5% and about 40% of the light in theorange-red spectral ranges (e.g., between about 580 nm and about 650nm).

Comparing the embodiments of the lenses for engaging in snow sports inlow light, bright light and bright and/or low light, it is noted thatembodiments of lenses configured for engaging in snow sports in lowlight transmit more light as compared to embodiments of lensesconfigured for engaging in snow sports in bright light and bright and/orlow light so as to allow the snow sportsman to see clearly in low light.It is further noted that embodiments of lenses configured for engagingin snow sports in bright light alone transmit less light as compared toembodiments of lenses configured for engaging in snow sports in brightand/or low light transmit so as to reduce the overall brightness andstrain on the eyes.

It is further observed from FIG. 6B that the second pass-band forembodiments of lenses for engaging in snow sports in different lightingconditions have a plateau shaped region between about 490 nm and about530 nm such that substantially all the wavelengths in the wavelengthbetween about 490 nm and about 530 nm are transmitted with almost equalintensity. In contrast, the first and third pass-bands for embodimentsof lenses for engaging in snow sports in different lighting conditionshave a bell-shaped profile. It is observed from FIG. 6B that the FWHM ofthe first pass-band for embodiments of lenses for engaging in snowsports in low light (represented by solid line) is about 30 nm around acentral wavelength of about 425 nm; and the FW80M of the third pass-bandfor embodiments of lenses for engaging in snow sports in low light isabout 40-50 nm around a central wavelength of about 630 nm.

It is further observed from FIG. 6B that that the FWHM of the firstpass-band for embodiments of lenses for engaging in snow sports inbright light (represented by dashed line) is about 30 nm around acentral wavelength of about 425 nm; and the FWHM of the third pass-bandfor embodiments of lenses for engaging in snow sports in bright light isabout 60-70 nm around a central wavelength of about 620 nm.

It is further observed from FIG. 6B that that the FWHM of the firstpass-band for embodiments of lenses for engaging in snow sports inbright and/or low light (represented by dash-dot line) is about 30 nmaround a central wavelength of about 425 nm; and the FW80M of the thirdpass-band for embodiments of lenses for engaging in snow sports inbright light and/or low light is about 40-50 nm around a centralwavelength of about 620 nm.

It is also observed from FIG. 6B that the effective transmittanceprofile for embodiments of lenses for engaging in snow sports indifferent lighting conditions can transmit between about 80% and about90% of light in the wavelength range between about 680 nm and about 790nm.

FIG. 6C illustrates three effective relative absorbance profiles ofoptical filter implementations that can be included in variousembodiments of lenses that are suitable for engaging in snow sports. Asdiscussed above, the relative absorbance profile is obtained by plottingthe term −log₁₀(% T_(λ)/τ_(v)) with respect to the wavelength (λ). Thefactor % T_(λ) represents the percentage of light transmitted throughthe one or more filters at a wavelength λ and the factor τ_(v)represents luminous transmittance as determined according to a techniquedefined in section 5.6.1 the ANSI Z80.3-2009 specification fornonprescription sunglass and fashion eyewear requirements. It isobserved from FIG. 6C that each of the relative absorbance profile has asimilar profile as the corresponding absorbance profile depicted in FIG.6A.

Comparing the relative absorbance for different embodiments of lensesfor engaging in snow sports in different lighting conditions, it isnoted that the embodiments of lenses configured for engaging in snowsports in bright light absorb wavelengths around red light to a greaterextent as compared to embodiments of lenses configured for engaging insnow sports in low or bright and/or low light. Furthermore, theembodiments of lenses configured for engaging in snow sports in brightlight absorb wavelengths around blue light to a lesser extent ascompared to embodiments of lenses configured for engaging in snow sportsin low or bright and/or low light. As discussed above, in variousembodiments of lenses including optical filters suitable for viewingobjects against snow can be tinted or have a chromaticity (e.g., pink,orange, red, brown, amber, yellow, etc.). For example, embodiments oflenses including optical filters that are adapted to view objectsagainst snow can have a CIE chromaticity x value of 0.35 or greater anda CIE chromaticity y value of 0.35. Various embodiments of lensesincluding optical filters that are adapted to view objects against snowcan have a CIE chromaticity x value greater than or equal to about 0.35,greater than or equal to about 0.38, greater than or equal to about 0.4and/or less than or equal to about 0.5. As another example,implementations of optical filters suitable for shooting can have a CIEchromaticity x value greater than or equal to about 0.37, greater thanor equal to about 0.39, greater than or equal to about 0.42 and/or lessthan or equal to about 0.6. Various embodiments of lenses includingoptical filters that are adapted to view objects against snow can have aCIE chromaticity y value between about 0.4 and about 0.5.

The embodiments of lenses including implementations of optical filtersthat are suitable for engaging in snow sports in bright light and/orbright and/or low light can include dielectric stacks, multilayerinterference coatings, rare earth oxide additives, organic dyes, or acombination of multiple polarization filters as described in U.S. Pat.No. 5,054,902, the entire contents of which are incorporated byreference herein and made a part of this specification for cosmeticpurposes and/or to darken various embodiments of the lenses. Someembodiments of interference coatings are sold by Oakley, Inc. ofFoothill Ranch, Calif., U.S.A. under the brand name Iridium®.

D. Filters to Provide Color Enhancement for Golf

Viewing a golf ball's trajectory and determining its location areimportant to golfers of various skill levels. Trajectories of a golfball hit by an inexperienced golfer are unpredictable and frequentlyplace the ball in locations in which the ball is hard to find. Suchfailures to promptly find a golf ball can increase the time used to playa round and can reduce the number of rounds that can be played on acourse in a day. Because time spent looking for errant golf ballscontributes to slow play, many courses and many tournaments have rulesconcerning how long a golfer is permitted to search for a lost golf ballbefore putting a replacement ball into play. For more experienced orexpert golfers, loss of a golf ball results in imposition of a penaltythat adds strokes to the golfer's score. Such penalty strokes areannoying, especially when the loss of a ball results from an inabilityto find the ball due to poor viewing conditions and a limited time inwhich to search. Moreover, the ability to visually discern varioustextures, tones and topography of the grass can be important to enhancea golfer's game. Accordingly, embodiments of lenses includingchroma-enhancing optical filters that enhance a golfers ability to seethe golf ball against the grass and see other obstacles and markers onthe golf course are advantageous.

Various embodiments of lenses used for golf preferably reduce glare(e.g., glare resulting from sunlight on a bright sunny day). Reducingglare can advantageously increase the ability of seeing the fairway, thehole and the ball thus allowing a golfer to play to the best of his/herability. Accordingly, various embodiments of lenses used for golf caninclude coatings, layers or films that reduce glare. The glare reducingcoatings, layers or films can include polarizing films and/or coatingsto filter out polarized light, holographic or diffractive elements thatare configured to reduce glare and/or diffusing elements. Additionally,it would be advantageous for various embodiments of lenses used for golfto include filters that make trees, sky and other objects (e.g., flags,water features, tree roots, etc.) stand-out from the green grass to aidthe golfer to guide the golf ball to a desired location. Making trees,sky and other objects stand-out from the green grass can also enhance aplayers golfing experience.

Various embodiments of lenses suitable for golfing can includeimplementations of optical filters that transmit different colors in thevisible spectral range with different values to create different viewingconditions. For example, some embodiments of lenses for golfing cantransmit all colors of the visible spectrum such that there is littledistortion on bright sunny days. As another example, some embodiments oflenses for golfing can transmit colors in the yellow and red spectralranges and attenuate and/or absorb colors in the blue and green spectralranges. Various embodiments of lenses used for golfing can also betinted (e.g., grey, green, amber, brown or yellow) to increase contrastbetween the grass and the sky, reduce eye strain and/or for aestheticpurpose.

FIGS. 7A-7C illustrate the effective spectral response of an opticalfilter implementation that can be included in an embodiment of a lensthat is suitable for golfing. FIG. 7A illustrates the effectiveabsorbance profile of the optical filter implementation that can beincluded in an embodiment of a lens that is suitable for golfing. FIGS.7B and 7C show the effective transmittance profile and the relativeabsorbance profile of the same optical filter implementation.

Referring to FIG. 7A, it is observed that the effective absorbanceprofile for the one or more lenses included in an embodiment of a lensthat is suitable for golfing has a first “valley” in the wavelengthrange between about 410 nm and about 460 nm; a second “valley” in thewavelength range between about 500 nm and about 560 nm; and a third“valley” in the wavelength range between about 600 nm and about 700 nm.Wavelengths in the first, second and third valleys have reducedabsorbance as compared to the wavelengths in the vicinity of the firstand second peaks. The valleys in the absorbance profile correspond tothe pass-bands in the transmittance profile. It is noted from FIG. 7Athat the first peak has a FWHM of about 25-30 nm around a centralwavelength of about 475 nm, the second peak has a FW80M of about 10-20nm around a central wavelength of about 575 nm and the third peak has aFW80M of about 15-20 nm around a central wavelength of about 660 nm.

It is observed from FIG. 7A that (i) the value of the optical densityfor wavelengths in the vicinity of the first peak around 475 nm is about300-400% higher as compared to the average value of the optical densityfor wavelengths in the first valley; and (ii) the value of the opticaldensity for wavelengths in the vicinity of the first peak around 475 nmis about 300% higher as compared to the average value of the opticaldensity for wavelengths in the second valley. Thus, wavelengths in thevicinity of the first peak around 475 nm are attenuated by about300-400% more as compared to wavelengths in the vicinity of the firstvalley and by about 300% more as compared to wavelengths in the vicinityof the second valley.

It is further observed from FIG. 7A that (i) the value of the opticaldensity for wavelengths in the vicinity of the second peak around 575 nmis about 100% higher as compared to the average value of the opticaldensity for wavelengths in the second valley; and (ii) the value of theoptical density for wavelengths in the vicinity of the second peakaround 575 nm is about 500% higher as compared to the average value ofthe optical density for wavelengths in the third valley. Thus,wavelengths in the vicinity of the second peak around 575 nm areattenuated by about 100% more as compared to wavelengths in the vicinityof the second valley and by about 500% more as compared to wavelengthsin the vicinity of the third valley.

It is further observed from FIG. 7A that (i) the value of the opticaldensity for wavelengths in the vicinity of the third peak around 660 nmis about 100% higher as compared to the average value of the opticaldensity for wavelengths in the third valley. Thus, wavelengths in thevicinity of the third peak around 660 nm are attenuated by about 100%more as compared to wavelengths in the vicinity of the third valley.

In various embodiments of lenses the implementation of an optical filterconfigured for use for golfing can be adapted to attenuate light havingwavelengths less than 400 nm thereby providing safety and healthbenefits. Furthermore, the attenuation factor of the absorbance peaks inthe blue spectral range (e.g., between about 450 nm and about 490 nm)and green spectral range (e.g., between about 550 nm and about 590 nm)can be greater than or equal to about 0.8 and less than 1 in variousimplementations of optical filters adapted for golfing. Additionally,the attenuation factor of the absorbance peaks in the red spectral range(e.g., between about 620 nm and about 660 nm) can be between about 0.5and about 0.8 in various implementations of optical filters adapted forgolfing. Without any loss of generality, the attenuation factor of anabsorbance peak can be obtained by dividing an integrated absorptancepeak area within the spectral bandwidth by the spectral bandwidth of theabsorbance peak.

In the illustrated transmittance profile in FIG. 7B, the effectivetransmittance profile of the optical filter implementation has a firstpass-band configured to transmit between about 1% to about 50% of lightin the violet-blue spectral ranges (e.g., between about 405 nm and about470 nm); a second pass-band configured to transmit between about 1% andabout 30% of the light in the green-yellow spectral ranges (e.g.,between about 490 nm and about 570 nm); and a third pass-band configuredto transmit between about 10% and about 75% of the light in theorange-red spectral ranges (e.g., between about 580 nm and about 660nm).

It is further observed from FIG. 7B that the second pass-band for anembodiment of a lens suitable for golfing has a plateau shaped regionbetween about 490 nm and about 530 nm such that substantially all thewavelengths in the wavelength range between about 490 nm and about 530nm are transmitted with almost equal intensity. In contrast, the firstand third pass-bands for an embodiment of a lens for golfing have abell-shaped profile. It is observed from FIG. 7B that the FWHM of thefirst pass-band for an embodiment of a lens for golfing is about 35 nmaround a central wavelength of about 425 nm; and the FWHM of the thirdpass-band for embodiments of lenses for an embodiment of a lens forgolfing is about 50-60 nm around a central wavelength of about 625 nm.

It is also observed from FIG. 7B that the effective transmittanceprofile for an embodiment of a lens suitable for golfing can transmitbetween about 80% and about 90% of light in the wavelength range betweenabout 680 nm and about 790 nm.

FIG. 7C illustrates the effective relative absorbance profile of anembodiment of a lens including an optical filter implementation that canbe suitable for golfing. The relative absorbance profile is obtained byplotting the term −log₁₀(% T_(λ)/τ_(v)) with respect to the wavelength(λ). The factor % T_(λ) represents the percentage of light transmittedthrough the one or more filters at a wavelength λ and the factor τ_(v)represents luminous transmittance as determined according to a techniquedefined in section 5.6.1 the ANSI Z80.3-2009 specification fornonprescription sunglass and fashion eyewear requirements. It isobserved that the relative absorption has a similar profile as theabsorbance profile depicted in FIG. 7A. In various embodiments theoptical filter implementations can also be configured to provide a tintor chromaticity (e.g., orange, red, pink, brown, amber, yellow, etc.) tothe lens embodiments that are suitable for golfing. In variousembodiments, the implementations of optical filters suitable for golfingcan have a CIE chromaticity x value of 0.35 or greater. For example,implementations of optical filters suitable for golfing can have a CIEchromaticity x value greater than or equal to about 0.35, greater thanor equal to about 0.38, greater than or equal to about 0.4 and/or lessthan or equal to about 0.5. As another example, implementations ofoptical filters suitable for shooting can have a CIE chromaticity xvalue greater than or equal to about 0.37, greater than or equal toabout 0.39, greater than or equal to about 0.42 and/or less than orequal to about 0.6.

The embodiments of lenses including implementations of optical filtersthat are suitable for golfing can include dielectric stacks, multilayerinterference coatings, rare earth oxide additives, organic dyes, or acombination of multiple polarization filters as described in U.S. Pat.No. 5,054,902, the entire contents of which are incorporated byreference herein and made a part of this specification for cosmeticpurposes and/or to darken various embodiments of the lenses. Someembodiments of interference coatings are sold by Oakley, Inc. ofFoothill Ranch, Calif., U.S.A. under the brand name Iridium®.

E. Filters to Provide Color Enhancement for Shooting

Various embodiments of lenses used for shooting (e.g., target shooting,hunting, etc.) preferably reduce glare (e.g., glare resulting fromsunlight on a bright sunny day). Reducing glare can advantageouslyincrease the ability of the shooter to see the target clearly.Accordingly, various embodiments of lenses used for shooting can includecoatings, layers or films that reduce glare. The glare reducingcoatings, layers or films can include polarizing films and/or coatingsto filter out polarized light, holographic or diffractive elements thatare configured to reduce glare and/or diffusing elements. Additionally,since the lighting conditions can change depending on the day, it wouldbe advantageous to tailor different embodiments of lenses for shootingfor different lighting conditions. For example, some embodiments oflenses for shooting can be configured for viewing in bright light, suchas on bright sunny days. As another example, some embodiments of lensesfor shooting can be configured for viewing in low light, such as oncloudy days. Various embodiments of lenses suitable for shooting caninclude implementations of optical filters that transmit differentcolors in the visible spectral range with different values to createdifferent viewing conditions. For example, some embodiments of lensessuitable for shooting can transmit all colors of the visible spectrumsuch that there is little distortion on bright sunny days. As anotherexample, some embodiments of lenses suitable for shooting can transmitcolors in the yellow and red spectral ranges and attenuate and/or absorbcolors in the blue and green spectral ranges. Various embodiments oflenses used for shooting can also be tinted (e.g., grey, green, amber,brown or yellow) to increase contrast between the target and the trees,reduce eye strain and/or for aesthetic purpose.

FIGS. 8A-8C illustrate the effective spectral response ofimplementations of optical filters that can be included in variousembodiments of lenses suitable for shooting. FIG. 8A illustrates twoeffective absorbance profiles of optical filter implementations that canbe included in various embodiments of lenses suitable for shooting. Thefirst effective absorbance profile represented by a solid linerepresents the effective absorbance profile of an optical filterimplementation that can be included in an embodiment of a lens that issuitable for engaging in shooting in low light. The second effectiveabsorbance profile represented by a dashed line represents the effectiveabsorbance profile of an optical filter implementation that can beincluded in an embodiment of a lens that is suitable for engaging inshooting in bright light. FIG. 8B illustrates two effectivetransmittance profiles of the same optical filter implementations thatcan be included in various embodiments of lenses suitable for shooting.The first effective transmittance profile represented by a solid linerepresents the effective transmittance profile of the same opticalfilter implementation that can be included in an embodiment of a lensthat is suitable for shooting in low light. The second effectivetransmittance profile represented by a dashed line represents theeffective transmittance profile of the same optical filterimplementation that can be included in an embodiment of a lens that issuitable for shooting in bright. FIG. 8C illustrates two effectiverelative absorbance profiles of the same optical filter implementationsthat can be included in various embodiments of lenses suitable forshooting. The first relative absorbance profile represented by a solidline represents the effective relative absorbance profile of the sameoptical filter implementation that can be included in an embodiment of alens that is suitable for shooting in low light. The second effectiverelative absorbance profile represented by a dashed line represents theeffective relative absorbance profile of the same optical filterimplementation that can be included in an embodiment of a lens that issuitable for shooting in bright light.

As discussed above, the effective absorbance profile depicted in FIG. 8Aexhibits peaks and valleys that correspond to the pass-bands and notchesexhibited by the corresponding effective transmittance profile depictedin FIG. 8B.

Referring to FIG. 8A, the effective absorbance profiles for the opticalfilter implementations included in embodiments of lenses suitable forshooting in different lighting conditions each has a first peak betweenabout 460 nm and 490 nm and a second peak between about 560 nm and 590nm. The effective absorbance profile for the optical filterimplementations included in embodiments of lenses suitable for shootingin different lighting conditions each has a first valley in thewavelength range between about 410 nm and about 460 nm; a second valleyin the wavelength range between about 500 nm and about 560 nm; and athird valley in the wavelength range between about 590 nm and about 640nm. As discussed above, wavelengths in the first, second and thirdvalleys have reduced absorbance as compared to the wavelengths in thevicinity of the first and second peaks.

Referring to the effective absorbance profile, depicted in FIG. 8A, forthe implementations of optical filters included in embodiments of lensessuitable for shooting in low light represented by the solid line, it isobserved that the first peak has a full width at half maximum (FWHM) ofabout 25-30 nm around a central wavelength of about 475 nm and thesecond peak has a FW80M of about 10-15 nm around a central wavelength ofabout 575 nm.

Referring to the effective absorbance profile, depicted in FIG. 8A, forthe implementations of optical filters included in embodiments of lensessuitable for shooting in low light represented by the solid line, it isobserved that (i) the value of the optical density for wavelengths inthe vicinity of the first peak around 475 nm is about 200% higher ascompared to the average value of the optical density for wavelengths inthe first valley; (ii) the value of the optical density for wavelengthsin the vicinity of the first peak around 475 nm is about 200% higher ascompared to the average value of the optical density for wavelengths inthe second valley. Thus, wavelengths in the vicinity of the first peakaround 475 nm are attenuated by about 200% more as compared towavelengths in the vicinity of the first valley and the second valley.

Referring to the effective absorbance profile, depicted in FIG. 8A, forthe implementation of the optical filter included in embodiments oflenses suitable for shooting in low light represented by the solid line,it is observed that (i) the value of the optical density for wavelengthsin the vicinity of the second peak around 575 nm is about 100% higher ascompared to the average value of the optical density for wavelengths inthe second valley, and (ii) the value of the optical density forwavelengths in the vicinity of the second peak around 575 nm is about500-600% higher as compared to the average value of the optical densityfor wavelengths in the third valley. Thus, wavelengths in the vicinityof the second peak around 575 nm are attenuated by about 100% more ascompared to wavelengths in the vicinity of the second valley and byabout 500-600% more as compared to wavelengths in the vicinity of thethird valley.

Referring to the effective absorbance profile, depicted in FIG. 8A, forthe optical filter implementations included in embodiments of lensessuitable for shooting in bright light represented by the dashed line, itis observed that the first peak has a full width at half maximum (FWHM)of about 30-35 nm around a central wavelength of about 475 nm, thesecond peak has a full width at 90% maximum (FW90M) of about 10-15 nmaround a central wavelength of about 575 nm.

Referring to the effective absorbance profile, depicted in FIG. 8A, forthe implementation of the optical filter included in embodiments oflenses suitable for shooting in bright light represented by the dashedline, it is observed that (i) the value of the optical density forwavelengths in the vicinity of the first peak around 475 nm is about150% higher as compared to the average value of the optical density forwavelengths in the first valley; (ii) the value of the optical densityfor wavelengths in the vicinity of the first peak around 475 nm is about150% higher as compared to the average value of the optical density forwavelengths in the second valley. Thus, wavelengths in the vicinity ofthe first peak around 475 nm are attenuated by about 150% more ascompared to wavelengths in the vicinity of the first and the secondvalley.

Referring to the effective absorbance profile, depicted in FIG. 8A, forthe implementation of the optical filter included in embodiments oflenses suitable for shooting in bright light represented by the dashedline, it is observed that (i) the value of the optical density forwavelengths in the vicinity of the second peak around 575 nm is about40% higher as compared to the average value of the optical density forwavelengths in the second valley; and (ii) the value of the opticaldensity for wavelengths in the vicinity of the second peak around 575 nmis about 100% higher as compared to the average value of the opticaldensity for wavelengths in the third valley. Thus, wavelengths in thevicinity of the second peak around 575 nm are attenuated by about 40%more as compared to wavelengths in the vicinity of the second valley andby about 100% more as compared to wavelengths in the vicinity of thethird valley.

The attenuation factor of the absorbance peaks in the blue spectralrange (e.g., between about 450 nm and about 490 nm) and green spectralregions (e.g., between about 550 nm and 590 nm) can be greater than orequal to about 0.8 and less than 1 in various implementations of opticalfilters adapted for shooting. The attenuation factor of the absorbancepeaks in the red spectral range (e.g., between about 630 nm and about660 nm) can be between about 0.4 and about 0.8 in variousimplementations of optical filters adapted for shooting. Without anyloss of generality, the attenuation factor of an absorbance peak can beobtained by dividing an integrated absorptance peak area within thespectral bandwidth by the spectral bandwidth of the absorbance peak.

Furthermore, the implementations of optical filters included in theembodiment of the lens suitable for shooting in different lightingconditions can be configured to attenuate light having wavelengths lessthan 400 nm (e.g., in the ultraviolet range) thereby providing safetyand health benefits.

As discussed above, the peaks in the effective absorbance profilecorresponds to notches in the effective transmittance profile. Thepresence of notches in the effective transmittance profile createsdistinct pass-bands. Wavelengths in each of the distinct pass-bands aretransmitted with lower attenuation than wavelengths in the notches. Inthe transmittance profile illustrated in FIG. 8B, the effectivetransmittance profile of the one or more filters in an embodiment of thelens suitable for engaging in shooting in low light (represented by asolid line) has a first pass-band configured to transmit between about1% to about 60% of light in the violet-blue spectral ranges (e.g.,between about 405 nm and about 460 nm); a second pass-band configured totransmit between about 5% and about 45% of the light in the green-yellowspectral ranges (e.g., between about 490 nm and about 570 nm); and athird pass-band configured to transmit between about 20% and about 80%of the light in the orange-red spectral ranges (e.g., between about 580nm and about 650 nm).

In the transmittance profile illustrated in FIG. 8B, the effectivetransmittance profile of the implementation of optical filter in anembodiment of the lens suitable for engaging in shooting in bright light(represented by a dashed line) has a first pass-band configured totransmit between about 1% to about 30% of light in the violet-bluespectral ranges (e.g., between about 405 nm and about 460 nm); a secondpass-band configured to transmit between about 1% and about 20% of thelight in the green-yellow spectral ranges (e.g., between about 490 nmand about 570 nm); and a third pass-band configured to transmit betweenabout 10% and about 35% of the light in the orange-red spectral ranges(e.g., between about 580 nm and about 650 nm).

Comparing the embodiments of the lenses for engaging in shooting in lowlight and, bright light, it is noted that embodiments of lensesconfigured for engaging in shooting in low light transmit more light ascompared to embodiments of lenses configured for engaging in shooting inbright light so as to allow the shooter to see clearly in low light.Transmitting less light in bright conditions can also advantageouslyreduce the overall strain on the eyes in bright conditions.

It is further observed from FIG. 8B that the second pass-band forembodiments of lenses for engaging in shooting in different lightingconditions have a plateau shaped region between about 490 nm and about560 nm such that substantially all the wavelengths in the wavelengthbetween about 490 nm and about 560 nm are transmitted with almost equalintensity. In contrast, the first and third pass-bands for embodimentsof lenses for engaging in shooting in different lighting conditions havea bell-shaped profile. It is observed from FIG. 8B that the FWHM of thefirst pass-band for embodiments of lenses for engaging in shooting inlow light is about 40-50 nm around a central wavelength of about 425 nm;and the FW90M of the third pass-band for embodiments of lenses forengaging in shooting in low light is about 40-50 nm around a centralwavelength of about 620 nm.

It is further observed from FIG. 8B that that the FWHM of the firstpass-band for embodiments of lenses for engaging in shooting in brightlight is about 40-50 nm around a central wavelength of about 425 nm; andthe FW90M of the third pass-band for embodiments of lenses for engagingin shooting in bright light is about 40-50 nm around a centralwavelength of about 620 nm.

It is also observed from FIG. 8B that the effective transmittanceprofile for embodiments of lenses engaging in shooting in differentlighting conditions can transmit between about 80% and about 90% oflight in the wavelength range between about 680 nm and about 790 nm.

FIG. 8C illustrates two effective relative absorbance profiles ofimplementations of an optical filter that can be included in variousembodiments of a lens that configured for engaging in shooting underdifferent lighting conditions. As discussed above, the relativeabsorbance profile is obtained by plotting the term −log₁₀(%T_(λ)/τ_(v)) with respect to the wavelength (λ). The factor % T_(λ)represents the percentage of light transmitted through the opticalfilter implementations at a wavelength λ and the factor τ_(v) representsluminous transmittance as determined according to a technique defined insection 5.6.1 the ANSI Z80.3-2009 specification for nonprescriptionsunglass and fashion eyewear requirements. It is observed from FIG. 8Cthat each of the relative absorbance profile has a similar profile asthe corresponding absorbance profile depicted in FIG. 8A. In variousembodiments the optical filter implementations can also be configured toprovide a tint or chromaticity (e.g., orange, red, pink, brown, amber,yellow, etc.) to the lens embodiments that are suitable for shooting. Invarious embodiments, the implementations of optical filters suitable forshooting can have a CIE chromaticity x value of 0.35 or greater. Forexample, implementations of optical filters suitable for shooting canhave a CIE chromaticity x value greater than or equal to about 0.35,greater than or equal to about 0.38, greater than or equal to about 0.4and/or less than or equal to about 0.5. As another example,implementations of optical filters suitable for shooting can have a CIEchromaticity x value greater than or equal to about 0.37, greater thanor equal to about 0.39, greater than or equal to about 0.42 and/or lessthan or equal to about 0.6.

The embodiments of lenses including implementations of optical filtersthat are suitable for shooting can include dielectric stacks, multilayerinterference coatings, rare earth oxide additives, organic dyes, or acombination of multiple polarization filters as described in U.S. Pat.No. 5,054,902, the entire contents of which are incorporated byreference herein and made a part of this specification for cosmeticpurposes and/or to darken various embodiments of the lenses. Someembodiments of interference coatings are sold by Oakley, Inc. ofFoothill Ranch, Calif., U.S.A. under the brand name Iridium®.

CONCLUSION

The implementations of optical filters described above can becategorized into three categories: (a) adapted to view objects on thesurface of water or underwater; (b) adapted to view objects on grass;and (c) adapted to view objects on snow. The characteristic of opticalfilters in each of the categories are summarized in the table below:

Position of the first Position of the second Position of the thirdabsorbance peak absorbance peak absorbance peak Attenuation AttenuationAttenuation Chromaticity Range Factor Range Factor Range Factor [x,y]Water 450 nm- >0.8; <1.0 550 nm- >0.8; <1.0 [>0.35, >0.35] 490 nm 590 nmGrass 450 nm- >0.8; <1.0 550 nm- >0.8; <1.0 630 nm- >0.3; <0.8[>0.35, >0.25] 490 nm 590 nm 670 nm Snow 450 nm- >0.8; <1.0 550nm- >0.8; <1.0 630 nm- >0.4; <0.9 [>0.35, >0.3] 490 nm 590 nm 670 nm

Additionally, various implementations of optical filters adapted to viewobjects on the surface of water or underwater can provide an averagechroma value increase in the blue spectral range (e.g., between about440 nm and about 490 nm) greater than about 10% (e.g., about 20%).Various implementations of optical filters adapted to view objects ongrass can provide an average chroma value increase in the blue spectralrange (e.g., between about 440 nm and about 490 nm) greater than about15% (e.g., between about 20%-40%). Various implementations of opticalfilters adapted to view objects on snow can provide an average chromavalue increase in the blue spectral range (e.g., between about 440 nmand about 490 nm) greater than about 15% (e.g., between about 209%-40%).

It is contemplated that the particular features, structures, orcharacteristics of any embodiments discussed herein can be combined inany suitable manner in one or more separate embodiments not expresslyillustrated or described. For example, it is understood that an opticalfilter can include any suitable combination of light attenuationfeatures and that a combination of light-attenuating lens elements cancombine to control the chroma of an image viewed through a lens. In manycases, structures that are described or illustrated as unitary orcontiguous can be separated while still performing the function(s) ofthe unitary structure. In many instances, structures that are describedor illustrated as separate can be joined or combined while stillperforming the function(s) of the separated structures. It is furtherunderstood that the optical filters disclosed herein can be used in atleast some lens configurations and/or optical systems besides thoseexplicitly disclosed herein. Any conflict that may exist between thisdisclosure and disclosure that is incorporated by reference should beresolved in favor of this disclosure.

It should be appreciated that in the above description of embodiments,various features are sometimes grouped together in a single embodiment,figure, or description thereof for the purpose of streamlining thedisclosure and aiding in the understanding of one or more of the variousinventive aspects. This method of disclosure, however, is not to beinterpreted as reflecting an intention that any claim require morefeatures than are expressly recited in that claim. Moreover, anycomponents, features, or steps illustrated and/or described in aparticular embodiment herein can be applied to or used with any otherembodiment(s). Thus, it is intended that the scope of the inventionsherein disclosed should not be limited by the particular embodimentsdescribed above, but should be determined by a fair reading of theclaims that follow.

What is claimed is:
 1. Eyewear comprising: a lens comprising an opticalfilter configured to attenuate visible light in one or more spectralbands, each of the one or more spectral bands comprising: an absorbancepeak with a spectral bandwidth and having a maximum absorbance, whereinthe absorbance peak is positioned in a middle portion of a respectivespectral band, wherein the middle portion is positioned between a lowerand an upper edge portion of the respective spectral band, whereinabsorbance within the upper and the lower edge portions is substantiallybelow the maximum absorbance; an absorptance peak associated with theabsorbance peak, the absorptance peak having a maximum absorptance; acenter wavelength located at a midpoint of the spectral bandwidth; anintegrated absorptance peak area within the spectral bandwidth; and anattenuation factor obtained by dividing the integrated absorptance peakarea within the spectral bandwidth by the spectral bandwidth of theabsorbance peak, wherein the spectral bandwidth is equal to the fullwidth of the absorbance peak at 90% of the maximum absorbance of theabsorbance peak; wherein the optical filter comprises a first absorbancepeak; wherein the center wavelength associated with the first absorbancepeak is in the wavelength range between about 440 nm and about 510 nm;wherein the absorptance peak associated with the first absorbance peakhas a maximum absorptance in the wavelength range between about 440 nmand about 510 nm; and wherein the spectral bandwidth associated with thefirst absorbance peak is less than or equal to 40 nm; wherein theattenuation factor of the first absorbance peak is greater than or equalto about 0.8 and less than
 1. 2. The eyewear of claim 1, wherein theoptical filter further comprises a second absorbance peak, wherein: thecenter wavelength associated with the second absorbance peak is in thewavelength range between about 580 nm and about 600 nm; the absorptancepeak associated with the second absorbance peak has a maximumabsorptance in the wavelength range between about 580 nm and about 600nm; and the attenuation factor of the second absorbance peak is greaterthan or equal to about 0.8 and less than
 1. 3. The eyewear of claim 2,wherein the optical filter further comprises a third absorbance peak,wherein: the center wavelength associated with the third absorbance peakis in the wavelength range between about 640 nm and about 680 nm; theabsorptance peak associated with the third absorbance peak has a maximumabsorptance in the wavelength range between about 640 nm and about 680nm; and the attenuation factor of the third absorbance peak is greaterthan or equal to about 0.8 and less than
 1. 4. The eyewear of claim 2,wherein the spectral bandwidth of the second absorbance peak is greaterthan or equal to about 5 nm and less than or equal to about 40 nm. 5.The eyewear of claim 1, wherein the spectral bandwidth of the firstabsorbance peak is greater than or equal to about 5 nm and less than orequal to about 40 nm.
 6. The eyewear of claim 1, wherein the opticalfilter further comprises one or more of organic dyes, plastic, acrylics,polycarbonates, dielectric stacks, rare earth oxide additives, or glass.7. The eyewear of claim 6, wherein the optical filter comprises one ormore organic dyes, wherein the one or more organic dyes are configuredto attenuate visible light in the one or more spectral bands.
 8. Theeyewear of claim 1, wherein the optical filter is configured to increasean average chroma value of uniform intensity light stimuli having abandwidth of 30 nm transmitted through the lens at least partiallywithin a spectral range of about 440 nm to about 480 nm by an amountbetween about 2% and about 20%, as compared to a neutral filter thatuniformly attenuates the same average percentage of light as the opticalfilter within the spectral range of about 440 nm to about 480 nm, whenoutputs resulting from uniform intensity inputs having a bandwidth of 30nm and a center wavelength within the spectral range are compared. 9.The eyewear of claim 1, wherein the optical filter is configured toincrease an average chroma value of uniform intensity light stimulihaving a bandwidth of 30 nm transmitted through the optical filterwithin a spectral range of about 540 nm to about 600 nm, as compared toa neutral filter that uniformly attenuates the same average percentageof light as the optical filter within the spectral range of about 540 nmto about 600 nm, when outputs resulting from uniform intensity inputshaving a bandwidth of 30 nm and a center wavelength within the spectralrange are compared.
 10. The eyewear of claim 1, wherein the lens has aCIE chromaticity y value greater than about 0.3.
 11. The eyewear ofclaim 1, wherein the lens has a CIE chromaticity x value greater thanabout 0.3.
 12. The eyewear of claim 1, wherein the optical filterfurther comprises a first absorbance valley adjacent to the firstabsorbance peak, wherein the first absorbance valley has a minimumabsorbance, and wherein an optical density associated with the firstabsorbance peak is about 40% higher than an optical density associatedwith the first absorbance valley.
 13. Eyewear comprising: a lenscomprising an optical filter configured to attenuate visible light inone or more spectral bands, each of the one or more spectral bandscomprising: an absorbance peak with a spectral bandwidth and having amaximum absorbance, wherein the absorbance peak is positioned in amiddle portion of a respective spectral band, wherein the middle portionis positioned between a lower and an upper edge portion of therespective spectral band, wherein absorbance within the upper and thelower edge portions is substantially below the maximum absorbance; anabsorptance peak associated with the absorbance peak, the absorptancepeak having a maximum absorptance; an integrated absorptance peak areawithin the spectral bandwidth; and an attenuation factor obtained bydividing the integrated absorptance peak area within the spectralbandwidth by the spectral bandwidth of the absorbance peak, wherein thespectral bandwidth is equal to the full width of the absorbance peak at90% of the maximum absorbance of the absorbance peak; wherein theoptical filter comprises a first chroma enhancement window having afirst absorbance peak within a spectral range of about 440 nm to about510 nm; wherein the absorptance peak associated with the firstabsorbance peak has a maximum absorptance in the wavelength rangebetween about 440 nm and about 510 nm; wherein the spectral bandwidthassociated with the first absorbance peak is less than or equal to 40nm; and wherein the attenuation factor of the first absorbance peak isgreater than or equal to about 0.8 and less than
 1. 14. The eyewear ofclaim 13, wherein an increase of average chroma value of uniformintensity light stimuli having a bandwidth of 30 nm transmitted throughthe lens at least partially within the first chroma enhancement windowis between about 2% and about 20% within a wavelength range betweenabout 440 nm and about 480 nm.
 15. The eyewear of claim 13, wherein anincrease of average chroma value of uniform intensity light stimulihaving a bandwidth of 30 nm transmitted through the lens at leastpartially within the first chroma enhancement window is larger than orequal to 0.1% within a wavelength range between about 440 nm and about510 nm.
 16. The eyewear of claim 13, wherein the optical filter furthercomprise a second chroma enhancement window having a second absorbancepeak within a spectral range of about 540 nm to about 600 nm, whereinthe absorptance peak associated with the second absorbance peak isbetween about 540 nm and about 600 nm and the attenuation factor of thesecond absorbance peak is greater than or equal to about 0.8 and lessthan
 1. 17. The eyewear of claim 16, wherein an increase of averagechroma value of uniform intensity light stimuli having a bandwidth of 30nm transmitted through the lens at least partially within the secondchroma enhancement window is between about 1% and about 5% within awavelength range between about 540 nm and about 600 nm.
 18. The eyewearof claim 13, wherein the lens has a CIE chromaticity y value betweenabout 0.3 and about 0.33.
 19. The eyewear of claim 13, wherein the lenshas a CIE chromaticity y value between about 0.31 and about 0.35. 20.The eyewear of claim 13, wherein the optical filter further comprises afirst absorbance valley adjacent to the first absorbance peak, whereinthe first absorbance valley has a reduced absorbance compared to theabsorbance of the first absorbance peak, and wherein an optical densityassociated with the first absorbance peak is about 40% higher than thatassociated with the first absorbance valley.
 21. The eyewear of claim13, further comprising a coating disposed over at least one surface ofthe lens, wherein the optical filter is at least partially incorporatedin the coating.
 22. Eyewear comprising: a lens comprising an opticalfilter configured to attenuate visible light in one or more spectralbands, each of the one or more spectral bands comprising: an absorbancepeak, wherein the absorbance peak has a spectral bandwidth, a maximumabsorbance, an optical density associated with the maximum absorbance,lower and upper edge portions that are substantially below the maximumabsorbance, and a middle portion positioned between the lower and upperedge portions including the maximum absorbance and a regionsubstantially near the maximum absorbance; and an absorbance valleyassociated with the absorbance peak, wherein the absorbance valley has aminimum absorbance, an optical density associated with the minimumabsorbance, lower and upper edge portions that are substantially abovethe minimum absorbance, and a middle portion positioned between thelower and upper edge portions including the minimum absorbance and aregion substantially near the minimum absorbance, wherein the absorbancevalley is positioned within the lower or upper edge portions associatedwith the absorbance peak, wherein the spectral bandwidth is equal to thefull width of the absorbance peak at 80% of the maximum absorbance ofthe absorbance peak; wherein the optical filter comprises a firstabsorbance peak and a first absorbance valley associated with the firstabsorbance peak; wherein the first absorbance peak is in the wavelengthrange between about 470 nm and about 510 nm; wherein the firstabsorbance valley is in the wavelength range between about 410 nm andabout 460 nm; wherein the optical density associated with the firstabsorbance peak is at least 40% higher than that associated with thefirst absorbance valley.
 23. The eyewear of claim 22, wherein thespectral bandwidth of the first absorbance peak is greater than or equalto about 5 nm and less than or equal to about 50 nm.
 24. The eyewear ofclaim 22, wherein the lens has a CIE chromaticity x value greater thanabout 0.3.
 25. The eyewear of claim 22, wherein the optical filterfurther comprises a second absorbance peak in the wavelength rangebetween about 580 nm and about 600 nm, and a second absorbance valley,associated with the second absorbance peak, in the wavelength rangebetween about 500 nm and about 560 nm, wherein the optical densityassociated with the second absorbance peak is at least 35% higher thanthat associated with the second absorbance valley.
 26. The eyewear ofclaim 25, wherein the optical filter further comprises a thirdabsorbance peak in the wavelength range between 640 nm and about 680 nm,and a third absorbance valley, associated with the third absorbancepeak, in the wavelength range between about 600 nm and about 650 nm,wherein the optical density associated with the third absorbance peak isat least 100% higher than that associated with the third absorbancevalley.